Merge tag 'tty-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty/serial driver updates for 5.17-rc1.

  Nothing major in here, just lots of good updates and fixes, including:

   - more tty core cleanups from Jiri as well as mxser driver cleanups.
     This is the majority of the core diffstat

   - tty documentation updates from Jiri

   - platform_get_irq() updates

   - various serial driver updates for new features and hardware

   - fifo usage for 8250 console, reducing cpu load a lot

   - LED fix for keyboards, long-time bugfix that went through many
     revisions

   - minor cleanups

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
  serial: core: Keep mctrl register state and cached copy in sync
  serial: stm32: correct loop for dma error handling
  serial: stm32: fix flow control transfer in DMA mode
  serial: stm32: rework TX DMA state condition
  serial: stm32: move tx dma terminate DMA to shutdown
  serial: pl011: Drop redundant DTR/RTS preservation on close/open
  serial: pl011: Drop CR register reset on set_termios
  serial: pl010: Drop CR register reset on set_termios
  serial: liteuart: fix MODULE_ALIAS
  serial: 8250_bcm7271: Fix return error code in case of dma_alloc_coherent() failure
  Revert "serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2"
  tty: goldfish: Use platform_get_irq() to get the interrupt
  serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2
  tty: serial: meson: Drop the legacy compatible strings and clock code
  serial: pmac_zilog: Use platform_get_irq() to get the interrupt
  serial: bcm63xx: Use platform_get_irq() to get the interrupt
  serial: ar933x: Use platform_get_irq() to get the interrupt
  serial: vt8500: Use platform_get_irq() to get the interrupt
  serial: altera_jtaguart: Use platform_get_irq_optional() to get the interrupt
  serial: pxa: Use platform_get_irq() to get the interrupt
  ...

47 files changed, 1951 insertions, 2149 deletions

diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
index d24af649a8bb..5ed19a9857ad 100644
--- a/drivers/tty/goldfish.c
+++ b/drivers/tty/goldfish.c
@@ -151,7 +151,7 @@ static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
 	address = (unsigned long)(void *)buf;
 	goldfish_tty_rw(qtty, address, count, 0);
 
-	tty_schedule_flip(&qtty->port);
+	tty_flip_buffer_push(&qtty->port);
 	return IRQ_HANDLED;
 }
 
@@ -298,7 +298,7 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 	struct resource *r;
 	struct device *ttydev;
 	void __iomem *base;
-	u32 irq;
+	int irq;
 	unsigned int line;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -313,14 +313,12 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!r) {
-		pr_err("goldfish_tty: No IRQ resource available!\n");
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
 		goto err_unmap;
 	}
 
-	irq = r->start;
-
 	mutex_lock(&goldfish_tty_lock);
 
 	if (pdev->id == PLATFORM_DEVID_NONE)
diff --git a/drivers/tty/mips_ejtag_fdc.c b/drivers/tty/mips_ejtag_fdc.c
index 02c10a968de1..31dceb5039b5 100644
--- a/drivers/tty/mips_ejtag_fdc.c
+++ b/drivers/tty/mips_ejtag_fdc.c
@@ -955,19 +955,18 @@ static int mips_ejtag_fdc_tty_probe(struct mips_cdmm_device *dev)
 		mips_ejtag_fdc_con.tty_drv = driver;
 
 	init_waitqueue_head(&priv->waitqueue);
-	priv->thread = kthread_create(mips_ejtag_fdc_put, priv, priv->fdc_name);
-	if (IS_ERR(priv->thread)) {
-		ret = PTR_ERR(priv->thread);
-		dev_err(priv->dev, "Couldn't create kthread (%d)\n", ret);
-		goto err_destroy_ports;
-	}
 	/*
 	 * Bind the writer thread to the right CPU so it can't migrate.
 	 * The channels are per-CPU and we want all channel I/O to be on a
 	 * single predictable CPU.
 	 */
-	kthread_bind(priv->thread, dev->cpu);
-	wake_up_process(priv->thread);
+	priv->thread = kthread_run_on_cpu(mips_ejtag_fdc_put, priv,
+					  dev->cpu, "ttyFDC/%u");
+	if (IS_ERR(priv->thread)) {
+		ret = PTR_ERR(priv->thread);
+		dev_err(priv->dev, "Couldn't create kthread (%d)\n", ret);
+		goto err_destroy_ports;
+	}
 
 	/* Look for an FDC IRQ */
 	priv->irq = get_c0_fdc_int();
@@ -1095,15 +1094,14 @@ static int mips_ejtag_fdc_tty_cpu_up(struct mips_cdmm_device *dev)
 	}
 
 	/* Restart the kthread */
-	priv->thread = kthread_create(mips_ejtag_fdc_put, priv, priv->fdc_name);
+	/* Bind it back to the right CPU and set it off */
+	priv->thread = kthread_run_on_cpu(mips_ejtag_fdc_put, priv,
+					  dev->cpu, "ttyFDC/%u");
 	if (IS_ERR(priv->thread)) {
 		ret = PTR_ERR(priv->thread);
 		dev_err(priv->dev, "Couldn't re-create kthread (%d)\n", ret);
 		goto out;
 	}
-	/* Bind it back to the right CPU and set it off */
-	kthread_bind(priv->thread, dev->cpu);
-	wake_up_process(priv->thread);
 out:
 	return ret;
 }
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index e37683e25055..f3c72ab1476c 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -1683,7 +1683,7 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
 		if (inited && !tty_throttled(tty) &&
 				MoxaPortRxQueue(p) > 0) { /* RX */
 			MoxaPortReadData(p);
-			tty_schedule_flip(&p->port);
+			tty_flip_buffer_push(&p->port);
 		}
 	} else {
 		clear_bit(EMPTYWAIT, &p->statusflags);
@@ -1708,7 +1708,7 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
 
 	if (tty && (intr & IntrBreak) && !I_IGNBRK(tty)) { /* BREAK */
 		tty_insert_flip_char(&p->port, 0, TTY_BREAK);
-		tty_schedule_flip(&p->port);
+		tty_flip_buffer_push(&p->port);
 	}
 
 	if (intr & IntrLine)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 93a95a135a71..c858aff721c4 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -159,14 +159,32 @@
 #define MXSER_BAUD_BASE		921600
 #define MXSER_CUSTOM_DIVISOR	(MXSER_BAUD_BASE * 16)
 
-#define PCI_DEVICE_ID_POS104UL	0x1044
-#define PCI_DEVICE_ID_CB108	0x1080
-#define PCI_DEVICE_ID_CP102UF	0x1023
-#define PCI_DEVICE_ID_CP112UL	0x1120
-#define PCI_DEVICE_ID_CB114	0x1142
-#define PCI_DEVICE_ID_CP114UL	0x1143
-#define PCI_DEVICE_ID_CB134I	0x1341
-#define PCI_DEVICE_ID_CP138U	0x1380
+#define PCI_DEVICE_ID_MOXA_RC7000	0x0001
+#define PCI_DEVICE_ID_MOXA_CP102	0x1020
+#define PCI_DEVICE_ID_MOXA_CP102UL	0x1021
+#define PCI_DEVICE_ID_MOXA_CP102U	0x1022
+#define PCI_DEVICE_ID_MOXA_CP102UF	0x1023
+#define PCI_DEVICE_ID_MOXA_C104		0x1040
+#define PCI_DEVICE_ID_MOXA_CP104U	0x1041
+#define PCI_DEVICE_ID_MOXA_CP104JU	0x1042
+#define PCI_DEVICE_ID_MOXA_CP104EL	0x1043
+#define PCI_DEVICE_ID_MOXA_POS104UL	0x1044
+#define PCI_DEVICE_ID_MOXA_CB108	0x1080
+#define PCI_DEVICE_ID_MOXA_CP112UL	0x1120
+#define PCI_DEVICE_ID_MOXA_CT114	0x1140
+#define PCI_DEVICE_ID_MOXA_CP114	0x1141
+#define PCI_DEVICE_ID_MOXA_CB114	0x1142
+#define PCI_DEVICE_ID_MOXA_CP114UL	0x1143
+#define PCI_DEVICE_ID_MOXA_CP118U	0x1180
+#define PCI_DEVICE_ID_MOXA_CP118EL	0x1181
+#define PCI_DEVICE_ID_MOXA_CP132	0x1320
+#define PCI_DEVICE_ID_MOXA_CP132U	0x1321
+#define PCI_DEVICE_ID_MOXA_CP134U	0x1340
+#define PCI_DEVICE_ID_MOXA_CB134I	0x1341
+#define PCI_DEVICE_ID_MOXA_CP138U	0x1380
+#define PCI_DEVICE_ID_MOXA_C168		0x1680
+#define PCI_DEVICE_ID_MOXA_CP168U	0x1681
+#define PCI_DEVICE_ID_MOXA_CP168EL	0x1682
 
 #define MXSER_NPORTS(ddata)		((ddata) & 0xffU)
 #define MXSER_HIGHBAUD			0x0100
@@ -194,32 +212,32 @@ static const struct {
 /* driver_data correspond to the lines in the structure above
    see also ISA probe function before you change something */
 static const struct pci_device_id mxser_pcibrds[] = {
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_C168),	.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_C104),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132),	.driver_data = 2 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP114),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CT114),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102),	.driver_data = 2 | MXSER_HIGHBAUD },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104U),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP168U),	.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132U),	.driver_data = 2 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP134U),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104JU),.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_RC7000),	.driver_data = 8 }, /* RC7000 */
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118U),	.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102UL),.driver_data = 2 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102U),	.driver_data = 2 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118EL),.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP168EL),.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104EL),.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB108),	.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB114),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB134I),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP138U),	.driver_data = 8 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_POS104UL),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP114UL),	.driver_data = 4 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP102UF),	.driver_data = 2 },
-	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP112UL),	.driver_data = 2 },
+	{ PCI_DEVICE_DATA(MOXA, C168,		8) },
+	{ PCI_DEVICE_DATA(MOXA, C104,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP132,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CT114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP102,		2 | MXSER_HIGHBAUD) },
+	{ PCI_DEVICE_DATA(MOXA, CP104U,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP168U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CP132U,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP134U,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP104JU,	4) },
+	{ PCI_DEVICE_DATA(MOXA, RC7000,		8) }, /* RC7000 */
+	{ PCI_DEVICE_DATA(MOXA, CP118U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CP102UL,	2) },
+	{ PCI_DEVICE_DATA(MOXA, CP102U,		2) },
+	{ PCI_DEVICE_DATA(MOXA, CP118EL,	8) },
+	{ PCI_DEVICE_DATA(MOXA, CP168EL,	8) },
+	{ PCI_DEVICE_DATA(MOXA, CP104EL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CB108,		8) },
+	{ PCI_DEVICE_DATA(MOXA, CB114,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CB134I,		4) },
+	{ PCI_DEVICE_DATA(MOXA, CP138U,		8) },
+	{ PCI_DEVICE_DATA(MOXA, POS104UL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CP114UL,	4) },
+	{ PCI_DEVICE_DATA(MOXA, CP102UF,	2) },
+	{ PCI_DEVICE_DATA(MOXA, CP112UL,	2) },
 	{ }
 };
 MODULE_DEVICE_TABLE(pci, mxser_pcibrds);
@@ -251,8 +269,6 @@ struct mxser_port {
 	u8 MCR;			/* Modem control register */
 	u8 FCR;			/* FIFO control register */
 
-	bool ldisc_stop_rx;
-
 	struct async_icount icount; /* kernel counters for 4 input interrupts */
 	unsigned int timeout;
 
@@ -262,7 +278,6 @@ struct mxser_port {
 	unsigned int xmit_head;
 	unsigned int xmit_tail;
 	unsigned int xmit_cnt;
-	int closing;
 
 	spinlock_t slock;
 };
@@ -684,27 +699,34 @@ static void mxser_change_speed(struct tty_struct *tty, struct ktermios *old_term
 	outb(cval, info->ioaddr + UART_LCR);
 }
 
-static void mxser_check_modem_status(struct tty_struct *tty,
-				struct mxser_port *port, int status)
+static u8 mxser_check_modem_status(struct tty_struct *tty,
+				struct mxser_port *port)
 {
+	u8 msr = inb(port->ioaddr + UART_MSR);
+
+	if (!(msr & UART_MSR_ANY_DELTA))
+		return msr;
+
 	/* update input line counters */
-	if (status & UART_MSR_TERI)
+	if (msr & UART_MSR_TERI)
 		port->icount.rng++;
-	if (status & UART_MSR_DDSR)
+	if (msr & UART_MSR_DDSR)
 		port->icount.dsr++;
-	if (status & UART_MSR_DDCD)
+	if (msr & UART_MSR_DDCD)
 		port->icount.dcd++;
-	if (status & UART_MSR_DCTS)
+	if (msr & UART_MSR_DCTS)
 		port->icount.cts++;
 	wake_up_interruptible(&port->port.delta_msr_wait);
 
-	if (tty_port_check_carrier(&port->port) && (status & UART_MSR_DDCD)) {
-		if (status & UART_MSR_DCD)
+	if (tty_port_check_carrier(&port->port) && (msr & UART_MSR_DDCD)) {
+		if (msr & UART_MSR_DCD)
 			wake_up_interruptible(&port->port.open_wait);
 	}
 
 	if (tty_port_cts_enabled(&port->port))
-		mxser_handle_cts(tty, port, status);
+		mxser_handle_cts(tty, port, msr);
+
+	return msr;
 }
 
 static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
@@ -802,6 +824,20 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
 }
 
 /*
+ * To stop accepting input, we disable the receive line status interrupts, and
+ * tell the interrupt driver to stop checking the data ready bit in the line
+ * status register.
+ */
+static void mxser_stop_rx(struct mxser_port *info)
+{
+	info->IER &= ~UART_IER_RLSI;
+	if (info->board->must_hwid)
+		info->IER &= ~MOXA_MUST_RECV_ISR;
+
+	outb(info->IER, info->ioaddr + UART_IER);
+}
+
+/*
  * This routine will shutdown a serial port
  */
 static void mxser_shutdown_port(struct tty_port *port)
@@ -811,6 +847,8 @@ static void mxser_shutdown_port(struct tty_port *port)
 
 	spin_lock_irqsave(&info->slock, flags);
 
+	mxser_stop_rx(info);
+
 	/*
 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
 	 * here so the queue might never be waken up
@@ -874,64 +912,9 @@ static void mxser_flush_buffer(struct tty_struct *tty)
 	tty_wakeup(tty);
 }
 
-
-static void mxser_close_port(struct tty_port *port)
-{
-	struct mxser_port *info = container_of(port, struct mxser_port, port);
-	unsigned long timeout;
-	/*
-	 * At this point we stop accepting input.  To do this, we
-	 * disable the receive line status interrupts, and tell the
-	 * interrupt driver to stop checking the data ready bit in the
-	 * line status register.
-	 */
-	info->IER &= ~UART_IER_RLSI;
-	if (info->board->must_hwid)
-		info->IER &= ~MOXA_MUST_RECV_ISR;
-
-	outb(info->IER, info->ioaddr + UART_IER);
-	/*
-	 * Before we drop DTR, make sure the UART transmitter
-	 * has completely drained; this is especially
-	 * important if there is a transmit FIFO!
-	 */
-	timeout = jiffies + HZ;
-	while (!(inb(info->ioaddr + UART_LSR) & UART_LSR_TEMT)) {
-		schedule_timeout_interruptible(5);
-		if (time_after(jiffies, timeout))
-			break;
-	}
-}
-
-/*
- * This routine is called when the serial port gets closed.  First, we
- * wait for the last remaining data to be sent.  Then, we unlink its
- * async structure from the interrupt chain if necessary, and we free
- * that IRQ if nothing is left in the chain.
- */
 static void mxser_close(struct tty_struct *tty, struct file *filp)
 {
-	struct mxser_port *info = tty->driver_data;
-	struct tty_port *port = &info->port;
-
-	if (info == NULL)
-		return;
-	if (tty_port_close_start(port, tty, filp) == 0)
-		return;
-	info->closing = 1;
-	mutex_lock(&port->mutex);
-	mxser_close_port(port);
-	mxser_flush_buffer(tty);
-	if (tty_port_initialized(port) && C_HUPCL(tty))
-		tty_port_lower_dtr_rts(port);
-	mxser_shutdown_port(port);
-	tty_port_set_initialized(port, 0);
-	mutex_unlock(&port->mutex);
-	info->closing = 0;
-	/* Right now the tty_port set is done outside of the close_end helper
-	   as we don't yet have everyone using refcounts */	
-	tty_port_close_end(port, tty);
-	tty_port_tty_set(port, NULL);
+	tty_port_close(tty->port, tty, filp);
 }
 
 static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -940,9 +923,6 @@ static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int cou
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
 
-	if (!info->port.xmit_buf)
-		return 0;
-
 	while (1) {
 		c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 					  SERIAL_XMIT_SIZE - info->xmit_head));
@@ -973,9 +953,6 @@ static int mxser_put_char(struct tty_struct *tty, unsigned char ch)
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
 
-	if (!info->port.xmit_buf)
-		return 0;
-
 	if (info->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
 		return 0;
 
@@ -993,7 +970,7 @@ static void mxser_flush_chars(struct tty_struct *tty)
 {
 	struct mxser_port *info = tty->driver_data;
 
-	if (!info->xmit_cnt || tty->flow.stopped || !info->port.xmit_buf ||
+	if (!info->xmit_cnt || tty->flow.stopped ||
 			(tty->hw_stopped && !mxser_16550A_or_MUST(info)))
 		return;
 
@@ -1153,25 +1130,24 @@ static int mxser_get_lsr_info(struct mxser_port *info,
 static int mxser_tiocmget(struct tty_struct *tty)
 {
 	struct mxser_port *info = tty->driver_data;
-	unsigned char control, status;
+	unsigned char control;
 	unsigned long flags;
+	u8 msr;
 
 	if (tty_io_error(tty))
 		return -EIO;
 
 	spin_lock_irqsave(&info->slock, flags);
 	control = info->MCR;
-	status = inb(info->ioaddr + UART_MSR);
-	if (status & UART_MSR_ANY_DELTA)
-		mxser_check_modem_status(tty, info, status);
+	msr = mxser_check_modem_status(tty, info);
 	spin_unlock_irqrestore(&info->slock, flags);
 
 	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
 		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
-		    ((status & UART_MSR_DCD) ? TIOCM_CAR : 0) |
-		    ((status & UART_MSR_RI) ? TIOCM_RNG : 0) |
-		    ((status & UART_MSR_DSR) ? TIOCM_DSR : 0) |
-		    ((status & UART_MSR_CTS) ? TIOCM_CTS : 0);
+		    ((msr & UART_MSR_DCD) ? TIOCM_CAR : 0) |
+		    ((msr & UART_MSR_RI) ? TIOCM_RNG : 0) |
+		    ((msr & UART_MSR_DSR) ? TIOCM_DSR : 0) |
+		    ((msr & UART_MSR_CTS) ? TIOCM_CTS : 0);
 }
 
 static int mxser_tiocmset(struct tty_struct *tty,
@@ -1326,11 +1302,14 @@ static int mxser_get_icount(struct tty_struct *tty,
 	return 0;
 }
 
-static void mxser_stoprx(struct tty_struct *tty)
+/*
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ */
+static void mxser_throttle(struct tty_struct *tty)
 {
 	struct mxser_port *info = tty->driver_data;
 
-	info->ldisc_stop_rx = true;
 	if (I_IXOFF(tty)) {
 		if (info->board->must_hwid) {
 			info->IER &= ~MOXA_MUST_RECV_ISR;
@@ -1349,21 +1328,11 @@ static void mxser_stoprx(struct tty_struct *tty)
 	}
 }
 
-/*
- * This routine is called by the upper-layer tty layer to signal that
- * incoming characters should be throttled.
- */
-static void mxser_throttle(struct tty_struct *tty)
-{
-	mxser_stoprx(tty);
-}
-
 static void mxser_unthrottle(struct tty_struct *tty)
 {
 	struct mxser_port *info = tty->driver_data;
 
 	/* startrx */
-	info->ldisc_stop_rx = false;
 	if (I_IXOFF(tty)) {
 		if (info->x_char)
 			info->x_char = 0;
@@ -1409,7 +1378,7 @@ static void mxser_start(struct tty_struct *tty)
 	unsigned long flags;
 
 	spin_lock_irqsave(&info->slock, flags);
-	if (info->xmit_cnt && info->port.xmit_buf)
+	if (info->xmit_cnt)
 		__mxser_start_tx(info);
 	spin_unlock_irqrestore(&info->slock, flags);
 }
@@ -1442,15 +1411,25 @@ static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termi
 	}
 }
 
+static bool mxser_tx_empty(struct mxser_port *info)
+{
+	unsigned long flags;
+	u8 lsr;
+
+	spin_lock_irqsave(&info->slock, flags);
+	lsr = inb(info->ioaddr + UART_LSR);
+	spin_unlock_irqrestore(&info->slock, flags);
+
+	return !(lsr & UART_LSR_TEMT);
+}
+
 /*
  * mxser_wait_until_sent() --- wait until the transmitter is empty
  */
 static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 {
 	struct mxser_port *info = tty->driver_data;
-	unsigned long orig_jiffies, char_time;
-	unsigned long flags;
-	int lsr;
+	unsigned long expire, char_time;
 
 	if (info->type == PORT_UNKNOWN)
 		return;
@@ -1458,7 +1437,6 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 	if (info->xmit_fifo_size == 0)
 		return;		/* Just in case.... */
 
-	orig_jiffies = jiffies;
 	/*
 	 * Set the check interval to be 1/5 of the estimated time to
 	 * send a single character, and make it at least 1.  The check
@@ -1473,6 +1451,9 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 		char_time = 1;
 	if (timeout && timeout < char_time)
 		char_time = timeout;
+
+	char_time = jiffies_to_msecs(char_time);
+
 	/*
 	 * If the transmitter hasn't cleared in twice the approximate
 	 * amount of time to send the entire FIFO, it probably won't
@@ -1485,18 +1466,15 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
 	if (!timeout || timeout > 2 * info->timeout)
 		timeout = 2 * info->timeout;
 
-	spin_lock_irqsave(&info->slock, flags);
-	while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
-		spin_unlock_irqrestore(&info->slock, flags);
-		schedule_timeout_interruptible(char_time);
-		spin_lock_irqsave(&info->slock, flags);
+	expire = jiffies + timeout;
+
+	while (mxser_tx_empty(info)) {
+		msleep_interruptible(char_time);
 		if (signal_pending(current))
 			break;
-		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+		if (time_after(jiffies, expire))
 			break;
 	}
-	spin_unlock_irqrestore(&info->slock, flags);
-	set_current_state(TASK_RUNNING);
 }
 
 /*
@@ -1531,8 +1509,7 @@ static int mxser_rs_break(struct tty_struct *tty, int break_state)
 	return 0;
 }
 
-static bool mxser_receive_chars_new(struct tty_struct *tty,
-		struct mxser_port *port, u8 status)
+static bool mxser_receive_chars_new(struct mxser_port *port, u8 status)
 {
 	enum mxser_must_hwid hwid = port->board->must_hwid;
 	u8 gdl;
@@ -1546,12 +1523,10 @@ static bool mxser_receive_chars_new(struct tty_struct *tty,
 	if (hwid == MOXA_MUST_MU150_HWID)
 		gdl &= MOXA_MUST_GDL_MASK;
 
-	if (gdl >= tty->receive_room && !port->ldisc_stop_rx)
-		mxser_stoprx(tty);
-
 	while (gdl--) {
 		u8 ch = inb(port->ioaddr + UART_RX);
-		tty_insert_flip_char(&port->port, ch, 0);
+		if (!tty_insert_flip_char(&port->port, ch, 0))
+			port->icount.buf_overrun++;
 	}
 
 	return true;
@@ -1561,10 +1536,8 @@ static u8 mxser_receive_chars_old(struct tty_struct *tty,
 		                struct mxser_port *port, u8 status)
 {
 	enum mxser_must_hwid hwid = port->board->must_hwid;
-	int recv_room = tty->receive_room;
 	int ignored = 0;
 	int max = 256;
-	int cnt = 0;
 	u8 ch;
 
 	do {
@@ -1599,14 +1572,10 @@ static u8 mxser_receive_chars_old(struct tty_struct *tty,
 					port->icount.overrun++;
 				}
 			}
-			tty_insert_flip_char(&port->port, ch, flag);
-			cnt++;
-			if (cnt >= recv_room) {
-				if (!port->ldisc_stop_rx)
-					mxser_stoprx(tty);
+			if (!tty_insert_flip_char(&port->port, ch, flag)) {
+				port->icount.buf_overrun++;
 				break;
 			}
-
 		}
 
 		if (hwid)
@@ -1621,10 +1590,7 @@ static u8 mxser_receive_chars_old(struct tty_struct *tty,
 static u8 mxser_receive_chars(struct tty_struct *tty,
 		struct mxser_port *port, u8 status)
 {
-	if (tty->receive_room == 0 && !port->ldisc_stop_rx)
-		mxser_stoprx(tty);
-
-	if (!mxser_receive_chars_new(tty, port, status))
+	if (!mxser_receive_chars_new(port, status))
 		status = mxser_receive_chars_old(tty, port, status);
 
 	tty_flip_buffer_push(&port->port);
@@ -1634,7 +1600,7 @@ static u8 mxser_receive_chars(struct tty_struct *tty,
 
 static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
 {
-	int count, cnt;
+	int count;
 
 	if (port->x_char) {
 		outb(port->x_char, port->ioaddr + UART_TX);
@@ -1643,27 +1609,22 @@ static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port
 		return;
 	}
 
-	if (port->port.xmit_buf == NULL)
-		return;
-
 	if (!port->xmit_cnt || tty->flow.stopped ||
 			(tty->hw_stopped && !mxser_16550A_or_MUST(port))) {
 		__mxser_stop_tx(port);
 		return;
 	}
 
-	cnt = port->xmit_cnt;
 	count = port->xmit_fifo_size;
 	do {
 		outb(port->port.xmit_buf[port->xmit_tail++],
 			port->ioaddr + UART_TX);
-		port->xmit_tail = port->xmit_tail & (SERIAL_XMIT_SIZE - 1);
+		port->xmit_tail &= SERIAL_XMIT_SIZE - 1;
+		port->icount.tx++;
 		if (!--port->xmit_cnt)
 			break;
 	} while (--count > 0);
 
-	port->icount.tx += (cnt - port->xmit_cnt);
-
 	if (port->xmit_cnt < WAKEUP_CHARS)
 		tty_wakeup(tty);
 
@@ -1674,7 +1635,7 @@ static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port
 static bool mxser_port_isr(struct mxser_port *port)
 {
 	struct tty_struct *tty;
-	u8 iir, msr, status;
+	u8 iir, status;
 	bool error = false;
 
 	iir = inb(port->ioaddr + UART_IIR);
@@ -1683,7 +1644,7 @@ static bool mxser_port_isr(struct mxser_port *port)
 
 	iir &= MOXA_MUST_IIR_MASK;
 	tty = tty_port_tty_get(&port->port);
-	if (!tty || port->closing || !tty_port_initialized(&port->port)) {
+	if (!tty) {
 		status = inb(port->ioaddr + UART_LSR);
 		outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
 				port->ioaddr + UART_FCR);
@@ -1707,9 +1668,7 @@ static bool mxser_port_isr(struct mxser_port *port)
 			status = mxser_receive_chars(tty, port, status);
 	}
 
-	msr = inb(port->ioaddr + UART_MSR);
-	if (msr & UART_MSR_ANY_DELTA)
-		mxser_check_modem_status(tty, port, msr);
+	mxser_check_modem_status(tty, port);
 
 	if (port->board->must_hwid) {
 		if (iir == 0x02 && (status & UART_LSR_THRE))
@@ -1836,7 +1795,6 @@ static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
 		tty_port_init(&info->port);
 		info->port.ops = &mxser_port_ops;
 		info->board = brd;
-		info->ldisc_stop_rx = false;
 
 		/* Enhance mode enabled here */
 		if (brd->must_hwid != MOXA_OTHER_UART)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 0b96b14bbfe1..ba27b274c967 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2074,8 +2074,6 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
 /**
  *	gsm_error		-	handle tty error
  *	@gsm: ldisc data
- *	@data: byte received (may be invalid)
- *	@flag: error received
  *
  *	Handle an error in the receipt of data for a frame. Currently we just
  *	go back to hunting for a SOF.
@@ -2083,8 +2081,7 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
  *	FIXME: better diagnostics ?
  */
 
-static void gsm_error(struct gsm_mux *gsm,
-				unsigned char data, unsigned char flag)
+static void gsm_error(struct gsm_mux *gsm)
 {
 	gsm->state = GSM_SEARCH;
 	gsm->io_error++;
@@ -2504,7 +2501,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 		case TTY_BREAK:
 		case TTY_PARITY:
 		case TTY_FRAME:
-			gsm_error(gsm, *cp, flags);
+			gsm_error(gsm);
 			break;
 		default:
 			WARN_ONCE(1, "%s: unknown flag %d\n",
@@ -2690,8 +2687,8 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
 	return mask;
 }
 
-static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
-		       unsigned int cmd, unsigned long arg)
+static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd,
+		       unsigned long arg)
 {
 	struct gsm_config c;
 	struct gsm_mux *gsm = tty->disc_data;
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 23ba1fc99df8..94c1ec2dd754 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -593,14 +593,13 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
 /**
  * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
  * @tty: pointer to tty instance data
- * @file: pointer to open file object for device
  * @cmd: IOCTL command code
  * @arg: argument for IOCTL call (cmd dependent)
  *
  * Returns command dependent result.
  */
-static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
-			    unsigned int cmd, unsigned long arg)
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+			    unsigned long arg)
 {
 	struct n_hdlc *n_hdlc = tty->disc_data;
 	int error = 0;
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 5be6d02dc690..a38fd65e39ab 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -186,17 +186,16 @@ static void tty_copy(struct tty_struct *tty, void *to, size_t tail, size_t n)
 }
 
 /**
- *	n_tty_kick_worker - start input worker (if required)
- *	@tty: terminal
+ * n_tty_kick_worker - start input worker (if required)
+ * @tty: terminal
  *
- *	Re-schedules the flip buffer work if it may have stopped
+ * Re-schedules the flip buffer work if it may have stopped.
  *
- *	Caller holds exclusive termios_rwsem
- *	   or
- *	n_tty_read()/consumer path:
- *		holds non-exclusive termios_rwsem
+ * Locking:
+ *  * Caller holds exclusive %termios_rwsem, or
+ *  * n_tty_read()/consumer path:
+ *	holds non-exclusive %termios_rwsem
  */
-
 static void n_tty_kick_worker(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -230,14 +229,12 @@ static ssize_t chars_in_buffer(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_write_wakeup	-	asynchronous I/O notifier
- *	@tty: tty device
+ * n_tty_write_wakeup	-	asynchronous I/O notifier
+ * @tty: tty device
  *
- *	Required for the ptys, serial driver etc. since processes
- *	that attach themselves to the master and rely on ASYNC
- *	IO must be woken up
+ * Required for the ptys, serial driver etc. since processes that attach
+ * themselves to the master and rely on ASYNC IO must be woken up.
  */
-
 static void n_tty_write_wakeup(struct tty_struct *tty)
 {
 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
@@ -300,16 +297,16 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 }
 
 /**
- *	put_tty_queue		-	add character to tty
- *	@c: character
- *	@ldata: n_tty data
+ * put_tty_queue		-	add character to tty
+ * @c: character
+ * @ldata: n_tty data
  *
- *	Add a character to the tty read_buf queue.
+ * Add a character to the tty read_buf queue.
  *
- *	n_tty_receive_buf()/producer path:
- *		caller holds non-exclusive termios_rwsem
+ * Locking:
+ *  * n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
  */
-
 static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
 {
 	*read_buf_addr(ldata, ldata->read_head) = c;
@@ -317,16 +314,16 @@ static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
 }
 
 /**
- *	reset_buffer_flags	-	reset buffer state
- *	@ldata: line disc data to reset
+ * reset_buffer_flags	-	reset buffer state
+ * @ldata: line disc data to reset
  *
- *	Reset the read buffer counters and clear the flags.
- *	Called from n_tty_open() and n_tty_flush_buffer().
+ * Reset the read buffer counters and clear the flags. Called from
+ * n_tty_open() and n_tty_flush_buffer().
  *
- *	Locking: caller holds exclusive termios_rwsem
- *		 (or locking is not required)
+ * Locking:
+ *  * caller holds exclusive %termios_rwsem, or
+ *  * (locking is not required)
  */
-
 static void reset_buffer_flags(struct n_tty_data *ldata)
 {
 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
@@ -351,19 +348,18 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_flush_buffer	-	clean input queue
- *	@tty:	terminal device
+ * n_tty_flush_buffer	-	clean input queue
+ * @tty: terminal device
  *
- *	Flush the input buffer. Called when the tty layer wants the
- *	buffer flushed (eg at hangup) or when the N_TTY line discipline
- *	internally has to clean the pending queue (for example some signals).
+ * Flush the input buffer. Called when the tty layer wants the buffer flushed
+ * (eg at hangup) or when the %N_TTY line discipline internally has to clean
+ * the pending queue (for example some signals).
  *
- *	Holds termios_rwsem to exclude producer/consumer while
- *	buffer indices are reset.
+ * Holds %termios_rwsem to exclude producer/consumer while buffer indices are
+ * reset.
  *
- *	Locking: ctrl.lock, exclusive termios_rwsem
+ * Locking: %ctrl.lock, exclusive %termios_rwsem
  */
-
 static void n_tty_flush_buffer(struct tty_struct *tty)
 {
 	down_write(&tty->termios_rwsem);
@@ -376,55 +372,50 @@ static void n_tty_flush_buffer(struct tty_struct *tty)
 }
 
 /**
- *	is_utf8_continuation	-	utf8 multibyte check
- *	@c: byte to check
+ * is_utf8_continuation	-	utf8 multibyte check
+ * @c: byte to check
  *
- *	Returns true if the utf8 character 'c' is a multibyte continuation
- *	character. We use this to correctly compute the on screen size
- *	of the character when printing
+ * Returns: true if the utf8 character @c is a multibyte continuation
+ * character. We use this to correctly compute the on-screen size of the
+ * character when printing.
  */
-
 static inline int is_utf8_continuation(unsigned char c)
 {
 	return (c & 0xc0) == 0x80;
 }
 
 /**
- *	is_continuation		-	multibyte check
- *	@c: byte to check
- *	@tty: terminal device
+ * is_continuation	-	multibyte check
+ * @c: byte to check
+ * @tty: terminal device
  *
- *	Returns true if the utf8 character 'c' is a multibyte continuation
- *	character and the terminal is in unicode mode.
+ * Returns: true if the utf8 character @c is a multibyte continuation character
+ * and the terminal is in unicode mode.
  */
-
 static inline int is_continuation(unsigned char c, struct tty_struct *tty)
 {
 	return I_IUTF8(tty) && is_utf8_continuation(c);
 }
 
 /**
- *	do_output_char			-	output one character
- *	@c: character (or partial unicode symbol)
- *	@tty: terminal device
- *	@space: space available in tty driver write buffer
+ * do_output_char	-	output one character
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ * @space: space available in tty driver write buffer
  *
- *	This is a helper function that handles one output character
- *	(including special characters like TAB, CR, LF, etc.),
- *	doing OPOST processing and putting the results in the
- *	tty driver's write buffer.
+ * This is a helper function that handles one output character (including
+ * special characters like TAB, CR, LF, etc.), doing OPOST processing and
+ * putting the results in the tty driver's write buffer.
  *
- *	Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
- *	and NLDLY.  They simply aren't relevant in the world today.
- *	If you ever need them, add them here.
+ * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY and NLDLY.
+ * They simply aren't relevant in the world today. If you ever need them, add
+ * them here.
  *
- *	Returns the number of bytes of buffer space used or -1 if
- *	no space left.
+ * Returns: the number of bytes of buffer space used or -1 if no space left.
  *
- *	Locking: should be called under the output_lock to protect
- *		 the column state and space left in the buffer
+ * Locking: should be called under the %output_lock to protect the column state
+ * and space left in the buffer.
  */
-
 static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -487,19 +478,18 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
 }
 
 /**
- *	process_output			-	output post processor
- *	@c: character (or partial unicode symbol)
- *	@tty: terminal device
+ * process_output	-	output post processor
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
  *
- *	Output one character with OPOST processing.
- *	Returns -1 when the output device is full and the character
- *	must be retried.
+ * Output one character with OPOST processing.
  *
- *	Locking: output_lock to protect column state and space left
- *		 (also, this is called from n_tty_write under the
- *		  tty layer write lock)
+ * Returns: -1 when the output device is full and the character must be
+ * retried.
+ *
+ * Locking: %output_lock to protect column state and space left (also, this is
+ *called from n_tty_write() under the tty layer write lock).
  */
-
 static int process_output(unsigned char c, struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -518,24 +508,23 @@ static int process_output(unsigned char c, struct tty_struct *tty)
 }
 
 /**
- *	process_output_block		-	block post processor
- *	@tty: terminal device
- *	@buf: character buffer
- *	@nr: number of bytes to output
- *
- *	Output a block of characters with OPOST processing.
- *	Returns the number of characters output.
- *
- *	This path is used to speed up block console writes, among other
- *	things when processing blocks of output data. It handles only
- *	the simple cases normally found and helps to generate blocks of
- *	symbols for the console driver and thus improve performance.
- *
- *	Locking: output_lock to protect column state and space left
- *		 (also, this is called from n_tty_write under the
- *		  tty layer write lock)
+ * process_output_block	-	block post processor
+ * @tty: terminal device
+ * @buf: character buffer
+ * @nr: number of bytes to output
+ *
+ * Output a block of characters with OPOST processing.
+ *
+ * This path is used to speed up block console writes, among other things when
+ * processing blocks of output data. It handles only the simple cases normally
+ * found and helps to generate blocks of symbols for the console driver and
+ * thus improve performance.
+ *
+ * Returns: the number of characters output.
+ *
+ * Locking: %output_lock to protect column state and space left (also, this is
+ * called from n_tty_write() under the tty layer write lock).
  */
-
 static ssize_t process_output_block(struct tty_struct *tty,
 				    const unsigned char *buf, unsigned int nr)
 {
@@ -596,30 +585,27 @@ break_out:
 }
 
 /**
- *	process_echoes	-	write pending echo characters
- *	@tty: terminal device
+ * __process_echoes	-	write pending echo characters
+ * @tty: terminal device
  *
- *	Write previously buffered echo (and other ldisc-generated)
- *	characters to the tty.
+ * Write previously buffered echo (and other ldisc-generated) characters to the
+ * tty.
  *
- *	Characters generated by the ldisc (including echoes) need to
- *	be buffered because the driver's write buffer can fill during
- *	heavy program output.  Echoing straight to the driver will
- *	often fail under these conditions, causing lost characters and
- *	resulting mismatches of ldisc state information.
+ * Characters generated by the ldisc (including echoes) need to be buffered
+ * because the driver's write buffer can fill during heavy program output.
+ * Echoing straight to the driver will often fail under these conditions,
+ * causing lost characters and resulting mismatches of ldisc state information.
  *
- *	Since the ldisc state must represent the characters actually sent
- *	to the driver at the time of the write, operations like certain
- *	changes in column state are also saved in the buffer and executed
- *	here.
+ * Since the ldisc state must represent the characters actually sent to the
+ * driver at the time of the write, operations like certain changes in column
+ * state are also saved in the buffer and executed here.
  *
- *	A circular fifo buffer is used so that the most recent characters
- *	are prioritized.  Also, when control characters are echoed with a
- *	prefixed "^", the pair is treated atomically and thus not separated.
+ * A circular fifo buffer is used so that the most recent characters are
+ * prioritized. Also, when control characters are echoed with a prefixed "^",
+ * the pair is treated atomically and thus not separated.
  *
- *	Locking: callers must hold output_lock
+ * Locking: callers must hold %output_lock.
  */
-
 static size_t __process_echoes(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -828,13 +814,12 @@ static void flush_echoes(struct tty_struct *tty)
 }
 
 /**
- *	add_echo_byte	-	add a byte to the echo buffer
- *	@c: unicode byte to echo
- *	@ldata: n_tty data
+ * add_echo_byte	-	add a byte to the echo buffer
+ * @c: unicode byte to echo
+ * @ldata: n_tty data
  *
- *	Add a character or operation byte to the echo buffer.
+ * Add a character or operation byte to the echo buffer.
  */
-
 static inline void add_echo_byte(unsigned char c, struct n_tty_data *ldata)
 {
 	*echo_buf_addr(ldata, ldata->echo_head) = c;
@@ -843,12 +828,11 @@ static inline void add_echo_byte(unsigned char c, struct n_tty_data *ldata)
 }
 
 /**
- *	echo_move_back_col	-	add operation to move back a column
- *	@ldata: n_tty data
+ * echo_move_back_col	-	add operation to move back a column
+ * @ldata: n_tty data
  *
- *	Add an operation to the echo buffer to move back one column.
+ * Add an operation to the echo buffer to move back one column.
  */
-
 static void echo_move_back_col(struct n_tty_data *ldata)
 {
 	add_echo_byte(ECHO_OP_START, ldata);
@@ -856,13 +840,12 @@ static void echo_move_back_col(struct n_tty_data *ldata)
 }
 
 /**
- *	echo_set_canon_col	-	add operation to set the canon column
- *	@ldata: n_tty data
+ * echo_set_canon_col	-	add operation to set the canon column
+ * @ldata: n_tty data
  *
- *	Add an operation to the echo buffer to set the canon column
- *	to the current column.
+ * Add an operation to the echo buffer to set the canon column to the current
+ * column.
  */
-
 static void echo_set_canon_col(struct n_tty_data *ldata)
 {
 	add_echo_byte(ECHO_OP_START, ldata);
@@ -870,20 +853,18 @@ static void echo_set_canon_col(struct n_tty_data *ldata)
 }
 
 /**
- *	echo_erase_tab	-	add operation to erase a tab
- *	@num_chars: number of character columns already used
- *	@after_tab: true if num_chars starts after a previous tab
- *	@ldata: n_tty data
- *
- *	Add an operation to the echo buffer to erase a tab.
- *
- *	Called by the eraser function, which knows how many character
- *	columns have been used since either a previous tab or the start
- *	of input.  This information will be used later, along with
- *	canon column (if applicable), to go back the correct number
- *	of columns.
+ * echo_erase_tab	-	add operation to erase a tab
+ * @num_chars: number of character columns already used
+ * @after_tab: true if num_chars starts after a previous tab
+ * @ldata: n_tty data
+ *
+ * Add an operation to the echo buffer to erase a tab.
+ *
+ * Called by the eraser function, which knows how many character columns have
+ * been used since either a previous tab or the start of input. This
+ * information will be used later, along with canon column (if applicable), to
+ * go back the correct number of columns.
  */
-
 static void echo_erase_tab(unsigned int num_chars, int after_tab,
 			   struct n_tty_data *ldata)
 {
@@ -901,16 +882,15 @@ static void echo_erase_tab(unsigned int num_chars, int after_tab,
 }
 
 /**
- *	echo_char_raw	-	echo a character raw
- *	@c: unicode byte to echo
- *	@ldata: line disc data
+ * echo_char_raw	-	echo a character raw
+ * @c: unicode byte to echo
+ * @ldata: line disc data
  *
- *	Echo user input back onto the screen. This must be called only when
- *	L_ECHO(tty) is true. Called from the driver receive_buf path.
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the &tty_driver.receive_buf() path.
  *
- *	This variant does not treat control characters specially.
+ * This variant does not treat control characters specially.
  */
-
 static void echo_char_raw(unsigned char c, struct n_tty_data *ldata)
 {
 	if (c == ECHO_OP_START) {
@@ -922,17 +902,16 @@ static void echo_char_raw(unsigned char c, struct n_tty_data *ldata)
 }
 
 /**
- *	echo_char	-	echo a character
- *	@c: unicode byte to echo
- *	@tty: terminal device
+ * echo_char		-	echo a character
+ * @c: unicode byte to echo
+ * @tty: terminal device
  *
- *	Echo user input back onto the screen. This must be called only when
- *	L_ECHO(tty) is true. Called from the driver receive_buf path.
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the &tty_driver.receive_buf() path.
  *
- *	This variant tags control characters to be echoed as "^X"
- *	(where X is the letter representing the control char).
+ * This variant tags control characters to be echoed as "^X" (where X is the
+ * letter representing the control char).
  */
-
 static void echo_char(unsigned char c, struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -948,10 +927,9 @@ static void echo_char(unsigned char c, struct tty_struct *tty)
 }
 
 /**
- *	finish_erasing		-	complete erase
- *	@ldata: n_tty data
+ * finish_erasing	-	complete erase
+ * @ldata: n_tty data
  */
-
 static inline void finish_erasing(struct n_tty_data *ldata)
 {
 	if (ldata->erasing) {
@@ -961,18 +939,17 @@ static inline void finish_erasing(struct n_tty_data *ldata)
 }
 
 /**
- *	eraser		-	handle erase function
- *	@c: character input
- *	@tty: terminal device
+ * eraser		-	handle erase function
+ * @c: character input
+ * @tty: terminal device
  *
- *	Perform erase and necessary output when an erase character is
- *	present in the stream from the driver layer. Handles the complexities
- *	of UTF-8 multibyte symbols.
+ * Perform erase and necessary output when an erase character is present in the
+ * stream from the driver layer. Handles the complexities of UTF-8 multibyte
+ * symbols.
  *
- *	n_tty_receive_buf()/producer path:
- *		caller holds non-exclusive termios_rwsem
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
  */
-
 static void eraser(unsigned char c, struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1091,20 +1068,6 @@ static void eraser(unsigned char c, struct tty_struct *tty)
 		finish_erasing(ldata);
 }
 
-/**
- *	isig		-	handle the ISIG optio
- *	@sig: signal
- *	@tty: terminal
- *
- *	Called when a signal is being sent due to terminal input.
- *	Called from the driver receive_buf path so serialized.
- *
- *	Performs input and output flush if !NOFLSH. In this context, the echo
- *	buffer is 'output'. The signal is processed first to alert any current
- *	readers or writers to discontinue and exit their i/o loops.
- *
- *	Locking: ctrl.lock
- */
 
 static void __isig(int sig, struct tty_struct *tty)
 {
@@ -1115,6 +1078,20 @@ static void __isig(int sig, struct tty_struct *tty)
 	}
 }
 
+/**
+ * isig			-	handle the ISIG optio
+ * @sig: signal
+ * @tty: terminal
+ *
+ * Called when a signal is being sent due to terminal input. Called from the
+ * &tty_driver.receive_buf() path, so serialized.
+ *
+ * Performs input and output flush if !NOFLSH. In this context, the echo
+ * buffer is 'output'. The signal is processed first to alert any current
+ * readers or writers to discontinue and exit their i/o loops.
+ *
+ * Locking: %ctrl.lock
+ */
 static void isig(int sig, struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1151,18 +1128,17 @@ static void isig(int sig, struct tty_struct *tty)
 }
 
 /**
- *	n_tty_receive_break	-	handle break
- *	@tty: terminal
+ * n_tty_receive_break	-	handle break
+ * @tty: terminal
  *
- *	An RS232 break event has been hit in the incoming bitstream. This
- *	can cause a variety of events depending upon the termios settings.
+ * An RS232 break event has been hit in the incoming bitstream. This can cause
+ * a variety of events depending upon the termios settings.
  *
- *	n_tty_receive_buf()/producer path:
- *		caller holds non-exclusive termios_rwsem
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive termios_rwsem
  *
- *	Note: may get exclusive termios_rwsem if flushing input buffer
+ * Note: may get exclusive %termios_rwsem if flushing input buffer
  */
-
 static void n_tty_receive_break(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1181,18 +1157,15 @@ static void n_tty_receive_break(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_receive_overrun	-	handle overrun reporting
- *	@tty: terminal
+ * n_tty_receive_overrun	-	handle overrun reporting
+ * @tty: terminal
  *
- *	Data arrived faster than we could process it. While the tty
- *	driver has flagged this the bits that were missed are gone
- *	forever.
+ * Data arrived faster than we could process it. While the tty driver has
+ * flagged this the bits that were missed are gone forever.
  *
- *	Called from the receive_buf path so single threaded. Does not
- *	need locking as num_overrun and overrun_time are function
- *	private.
+ * Called from the receive_buf path so single threaded. Does not need locking
+ * as num_overrun and overrun_time are function private.
  */
-
 static void n_tty_receive_overrun(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1207,15 +1180,15 @@ static void n_tty_receive_overrun(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_receive_parity_error	-	error notifier
- *	@tty: terminal device
- *	@c: character
+ * n_tty_receive_parity_error	-	error notifier
+ * @tty: terminal device
+ * @c: character
  *
- *	Process a parity error and queue the right data to indicate
- *	the error case if necessary.
+ * Process a parity error and queue the right data to indicate the error case
+ * if necessary.
  *
- *	n_tty_receive_buf()/producer path:
- *		caller holds non-exclusive termios_rwsem
+ * Locking: n_tty_receive_buf()/producer path:
+ * 	caller holds non-exclusive %termios_rwsem
  */
 static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)
 {
@@ -1247,19 +1220,6 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
 		process_echoes(tty);
 }
 
-/**
- *	n_tty_receive_char	-	perform processing
- *	@tty: terminal device
- *	@c: character
- *
- *	Process an individual character of input received from the driver.
- *	This is serialized with respect to itself by the rules for the
- *	driver above.
- *
- *	n_tty_receive_buf()/producer path:
- *		caller holds non-exclusive termios_rwsem
- *		publishes canon_head if canonical mode is active
- */
 static void n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1394,6 +1354,18 @@ handle_newline:
 	put_tty_queue(c, ldata);
 }
 
+/**
+ * n_tty_receive_char	-	perform processing
+ * @tty: terminal device
+ * @c: character
+ *
+ * Process an individual character of input received from the driver.  This is
+ * serialized with respect to itself by the rules for the driver above.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	caller holds non-exclusive %termios_rwsem
+ *	publishes canon_head if canonical mode is active
+ */
 static void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1594,38 +1566,37 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
 }
 
 /**
- *	n_tty_receive_buf_common	-	process input
- *	@tty: device to receive input
- *	@cp: input chars
- *	@fp: flags for each char (if NULL, all chars are TTY_NORMAL)
- *	@count: number of input chars in @cp
- *	@flow: enable flow control
- *
- *	Called by the terminal driver when a block of characters has
- *	been received. This function must be called from soft contexts
- *	not from interrupt context. The driver is responsible for making
- *	calls one at a time and in order (or using flush_to_ldisc)
- *
- *	Returns the # of input chars from @cp which were processed.
- *
- *	In canonical mode, the maximum line length is 4096 chars (including
- *	the line termination char); lines longer than 4096 chars are
- *	truncated. After 4095 chars, input data is still processed but
- *	not stored. Overflow processing ensures the tty can always
- *	receive more input until at least one line can be read.
- *
- *	In non-canonical mode, the read buffer will only accept 4095 chars;
- *	this provides the necessary space for a newline char if the input
- *	mode is switched to canonical.
- *
- *	Note it is possible for the read buffer to _contain_ 4096 chars
- *	in non-canonical mode: the read buffer could already contain the
- *	maximum canon line of 4096 chars when the mode is switched to
- *	non-canonical.
- *
- *	n_tty_receive_buf()/producer path:
- *		claims non-exclusive termios_rwsem
- *		publishes commit_head or canon_head
+ * n_tty_receive_buf_common	-	process input
+ * @tty: device to receive input
+ * @cp: input chars
+ * @fp: flags for each char (if %NULL, all chars are %TTY_NORMAL)
+ * @count: number of input chars in @cp
+ * @flow: enable flow control
+ *
+ * Called by the terminal driver when a block of characters has been received.
+ * This function must be called from soft contexts not from interrupt context.
+ * The driver is responsible for making calls one at a time and in order (or
+ * using flush_to_ldisc()).
+ *
+ * Returns: the # of input chars from @cp which were processed.
+ *
+ * In canonical mode, the maximum line length is 4096 chars (including the line
+ * termination char); lines longer than 4096 chars are truncated. After 4095
+ * chars, input data is still processed but not stored. Overflow processing
+ * ensures the tty can always receive more input until at least one line can be
+ * read.
+ *
+ * In non-canonical mode, the read buffer will only accept 4095 chars; this
+ * provides the necessary space for a newline char if the input mode is
+ * switched to canonical.
+ *
+ * Note it is possible for the read buffer to _contain_ 4096 chars in
+ * non-canonical mode: the read buffer could already contain the maximum canon
+ * line of 4096 chars when the mode is switched to non-canonical.
+ *
+ * Locking: n_tty_receive_buf()/producer path:
+ *	claims non-exclusive %termios_rwsem
+ *	publishes commit_head or canon_head
  */
 static int
 n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
@@ -1710,19 +1681,17 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 }
 
 /**
- *	n_tty_set_termios	-	termios data changed
- *	@tty: terminal
- *	@old: previous data
+ * n_tty_set_termios	-	termios data changed
+ * @tty: terminal
+ * @old: previous data
  *
- *	Called by the tty layer when the user changes termios flags so
- *	that the line discipline can plan ahead. This function cannot sleep
- *	and is protected from re-entry by the tty layer. The user is
- *	guaranteed that this function will not be re-entered or in progress
- *	when the ldisc is closed.
+ * Called by the tty layer when the user changes termios flags so that the line
+ * discipline can plan ahead. This function cannot sleep and is protected from
+ * re-entry by the tty layer. The user is guaranteed that this function will
+ * not be re-entered or in progress when the ldisc is closed.
  *
- *	Locking: Caller holds tty->termios_rwsem
+ * Locking: Caller holds @tty->termios_rwsem
  */
-
 static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1808,15 +1777,13 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 }
 
 /**
- *	n_tty_close		-	close the ldisc for this tty
- *	@tty: device
+ * n_tty_close		-	close the ldisc for this tty
+ * @tty: device
  *
- *	Called from the terminal layer when this line discipline is
- *	being shut down, either because of a close or becsuse of a
- *	discipline change. The function will not be called while other
- *	ldisc methods are in progress.
+ * Called from the terminal layer when this line discipline is being shut down,
+ * either because of a close or becsuse of a discipline change. The function
+ * will not be called while other ldisc methods are in progress.
  */
-
 static void n_tty_close(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
@@ -1831,15 +1798,13 @@ static void n_tty_close(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_open		-	open an ldisc
- *	@tty: terminal to open
+ * n_tty_open		-	open an ldisc
+ * @tty: terminal to open
  *
- *	Called when this line discipline is being attached to the
- *	terminal device. Can sleep. Called serialized so that no
- *	other events will occur in parallel. No further open will occur
- *	until a close.
+ * Called when this line discipline is being attached to the terminal device.
+ * Can sleep. Called serialized so that no other events will occur in parallel.
+ * No further open will occur until a close.
  */
-
 static int n_tty_open(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata;
@@ -1874,24 +1839,23 @@ static inline int input_available_p(struct tty_struct *tty, int poll)
 }
 
 /**
- *	copy_from_read_buf	-	copy read data directly
- *	@tty: terminal device
- *	@kbp: data
- *	@nr: size of data
- *
- *	Helper function to speed up n_tty_read.  It is only called when
- *	ICANON is off; it copies characters straight from the tty queue.
+ * copy_from_read_buf	-	copy read data directly
+ * @tty: terminal device
+ * @kbp: data
+ * @nr: size of data
  *
- *	Called under the ldata->atomic_read_lock sem
+ * Helper function to speed up n_tty_read(). It is only called when %ICANON is
+ * off; it copies characters straight from the tty queue.
  *
- *	Returns true if it successfully copied data, but there is still
- *	more data to be had.
+ * Returns: true if it successfully copied data, but there is still more data
+ * to be had.
  *
- *	n_tty_read()/consumer path:
- *		caller holds non-exclusive termios_rwsem
+ * Locking:
+ *  * called under the @ldata->atomic_read_lock sem
+ *  * n_tty_read()/consumer path:
+ *		caller holds non-exclusive %termios_rwsem;
  *		read_tail published
  */
-
 static bool copy_from_read_buf(struct tty_struct *tty,
 				      unsigned char **kbp,
 				      size_t *nr)
@@ -1926,28 +1890,27 @@ static bool copy_from_read_buf(struct tty_struct *tty,
 }
 
 /**
- *	canon_copy_from_read_buf	-	copy read data in canonical mode
- *	@tty: terminal device
- *	@kbp: data
- *	@nr: size of data
- *
- *	Helper function for n_tty_read.  It is only called when ICANON is on;
- *	it copies one line of input up to and including the line-delimiting
- *	character into the result buffer.
- *
- *	NB: When termios is changed from non-canonical to canonical mode and
- *	the read buffer contains data, n_tty_set_termios() simulates an EOF
- *	push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer.
- *	This causes data already processed as input to be immediately available
- *	as input although a newline has not been received.
- *
- *	Called under the atomic_read_lock mutex
- *
- *	n_tty_read()/consumer path:
- *		caller holds non-exclusive termios_rwsem
- *		read_tail published
+ * canon_copy_from_read_buf	-	copy read data in canonical mode
+ * @tty: terminal device
+ * @kbp: data
+ * @nr: size of data
+ *
+ * Helper function for n_tty_read(). It is only called when %ICANON is on; it
+ * copies one line of input up to and including the line-delimiting character
+ * into the result buffer.
+ *
+ * Note: When termios is changed from non-canonical to canonical mode and the
+ * read buffer contains data, n_tty_set_termios() simulates an EOF push (as if
+ * C-d were input) _without_ the %DISABLED_CHAR in the buffer. This causes data
+ * already processed as input to be immediately available as input although a
+ * newline has not been received.
+ *
+ * Locking:
+ *  * called under the %atomic_read_lock mutex
+ *  * n_tty_read()/consumer path:
+ *	caller holds non-exclusive %termios_rwsem;
+ *	read_tail published
  */
-
 static bool canon_copy_from_read_buf(struct tty_struct *tty,
 				     unsigned char **kbp,
 				     size_t *nr)
@@ -2015,19 +1978,19 @@ static bool canon_copy_from_read_buf(struct tty_struct *tty,
 }
 
 /**
- *	job_control		-	check job control
- *	@tty: tty
- *	@file: file handle
- *
- *	Perform job control management checks on this file/tty descriptor
- *	and if appropriate send any needed signals and return a negative
- *	error code if action should be taken.
- *
- *	Locking: redirected write test is safe
- *		 current->signal->tty check is safe
- *		 ctrl.lock to safely reference tty->ctrl.pgrp
+ * job_control		-	check job control
+ * @tty: tty
+ * @file: file handle
+ *
+ * Perform job control management checks on this @file/@tty descriptor and if
+ * appropriate send any needed signals and return a negative error code if
+ * action should be taken.
+ *
+ * Locking:
+ *  * redirected write test is safe
+ *  * current->signal->tty check is safe
+ *  * ctrl.lock to safely reference @tty->ctrl.pgrp
  */
-
 static int job_control(struct tty_struct *tty, struct file *file)
 {
 	/* Job control check -- must be done at start and after
@@ -2043,24 +2006,25 @@ static int job_control(struct tty_struct *tty, struct file *file)
 
 
 /**
- *	n_tty_read		-	read function for tty
- *	@tty: tty device
- *	@file: file object
- *	@buf: userspace buffer pointer
- *	@nr: size of I/O
- *
- *	Perform reads for the line discipline. We are guaranteed that the
- *	line discipline will not be closed under us but we may get multiple
- *	parallel readers and must handle this ourselves. We may also get
- *	a hangup. Always called in user context, may sleep.
- *
- *	This code must be sure never to sleep through a hangup.
- *
- *	n_tty_read()/consumer path:
- *		claims non-exclusive termios_rwsem
- *		publishes read_tail
+ * n_tty_read		-	read function for tty
+ * @tty: tty device
+ * @file: file object
+ * @kbuf: kernelspace buffer pointer
+ * @nr: size of I/O
+ * @cookie: if non-%NULL, this is a continuation read
+ * @offset: where to continue reading from (unused in n_tty)
+ *
+ * Perform reads for the line discipline. We are guaranteed that the line
+ * discipline will not be closed under us but we may get multiple parallel
+ * readers and must handle this ourselves. We may also get a hangup. Always
+ * called in user context, may sleep.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: n_tty_read()/consumer path:
+ *	claims non-exclusive termios_rwsem;
+ *	publishes read_tail
  */
-
 static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 			  unsigned char *kbuf, size_t nr,
 			  void **cookie, unsigned long offset)
@@ -2232,25 +2196,23 @@ more_to_be_read:
 }
 
 /**
- *	n_tty_write		-	write function for tty
- *	@tty: tty device
- *	@file: file object
- *	@buf: userspace buffer pointer
- *	@nr: size of I/O
- *
- *	Write function of the terminal device.  This is serialized with
- *	respect to other write callers but not to termios changes, reads
- *	and other such events.  Since the receive code will echo characters,
- *	thus calling driver write methods, the output_lock is used in
- *	the output processing functions called here as well as in the
- *	echo processing function to protect the column state and space
- *	left in the buffer.
- *
- *	This code must be sure never to sleep through a hangup.
- *
- *	Locking: output_lock to protect column state and space left
- *		 (note that the process_output*() functions take this
- *		  lock themselves)
+ * n_tty_write		-	write function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Write function of the terminal device. This is serialized with respect to
+ * other write callers but not to termios changes, reads and other such events.
+ * Since the receive code will echo characters, thus calling driver write
+ * methods, the %output_lock is used in the output processing functions called
+ * here as well as in the echo processing function to protect the column state
+ * and space left in the buffer.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: output_lock to protect column state and space left
+ *	 (note that the process_output*() functions take this lock themselves)
  */
 
 static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
@@ -2341,19 +2303,19 @@ break_out:
 }
 
 /**
- *	n_tty_poll		-	poll method for N_TTY
- *	@tty: terminal device
- *	@file: file accessing it
- *	@wait: poll table
+ * n_tty_poll		-	poll method for N_TTY
+ * @tty: terminal device
+ * @file: file accessing it
+ * @wait: poll table
+ *
+ * Called when the line discipline is asked to poll() for data or for special
+ * events. This code is not serialized with respect to other events save
+ * open/close.
  *
- *	Called when the line discipline is asked to poll() for data or
- *	for special events. This code is not serialized with respect to
- *	other events save open/close.
+ * This code must be sure never to sleep through a hangup.
  *
- *	This code must be sure never to sleep through a hangup.
- *	Called without the kernel lock held - fine
+ * Locking: called without the kernel lock held -- fine.
  */
-
 static __poll_t n_tty_poll(struct tty_struct *tty, struct file *file,
 							poll_table *wait)
 {
@@ -2400,8 +2362,8 @@ static unsigned long inq_canon(struct n_tty_data *ldata)
 	return nr;
 }
 
-static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
-		       unsigned int cmd, unsigned long arg)
+static int n_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
+		       unsigned long arg)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 	int retval;
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 6473361525d1..db784ace25d8 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -241,16 +241,8 @@ static inline int serial8250_in_MCR(struct uart_8250_port *up)
 	return mctrl;
 }
 
-#if defined(__alpha__) && !defined(CONFIG_PCI)
-/*
- * Digital did something really horribly wrong with the OUT1 and OUT2
- * lines on at least some ALPHA's.  The failure mode is that if either
- * is cleared, the machine locks up with endless interrupts.
- */
-#define ALPHA_KLUDGE_MCR  (UART_MCR_OUT2 | UART_MCR_OUT1)
-#else
-#define ALPHA_KLUDGE_MCR 0
-#endif
+bool alpha_jensen(void);
+void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl);
 
 #ifdef CONFIG_SERIAL_8250_PNP
 int serial8250_pnp_init(void);
diff --git a/drivers/tty/serial/8250/8250_alpha.c b/drivers/tty/serial/8250/8250_alpha.c
new file mode 100644
index 000000000000..58e70328aa4d
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_alpha.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <asm/machvec.h>
+#include "8250.h"
+
+bool alpha_jensen(void)
+{
+	return !strcmp(alpha_mv.vector_name, "Jensen");
+}
+
+void alpha_jensen_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/*
+	 * Digital did something really horribly wrong with the OUT1 and OUT2
+	 * lines on Alpha Jensen.  The failure mode is that if either is
+	 * cleared, the machine locks up with endless interrupts.
+	 */
+	mctrl |= TIOCM_OUT1 | TIOCM_OUT2;
+
+	serial8250_do_set_mctrl(port, mctrl);
+}
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index 5163d60756b7..9b878d023dac 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -941,7 +941,7 @@ static int brcmuart_probe(struct platform_device *pdev)
 	struct brcmuart_priv *priv;
 	struct clk *baud_mux_clk;
 	struct uart_8250_port up;
-	struct resource *irq;
+	int irq;
 	void __iomem *membase = NULL;
 	resource_size_t mapbase = 0;
 	u32 clk_rate = 0;
@@ -952,11 +952,9 @@ static int brcmuart_probe(struct platform_device *pdev)
 		"uart", "dma_rx", "dma_tx", "dma_intr2", "dma_arb"
 	};
 
-	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq) {
-		dev_err(dev, "missing irq\n");
-		return -EINVAL;
-	}
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 	priv = devm_kzalloc(dev, sizeof(struct brcmuart_priv),
 			GFP_KERNEL);
 	if (!priv)
@@ -1044,7 +1042,7 @@ static int brcmuart_probe(struct platform_device *pdev)
 	up.port.dev = dev;
 	up.port.mapbase = mapbase;
 	up.port.membase = membase;
-	up.port.irq = irq->start;
+	up.port.irq = irq;
 	up.port.handle_irq = brcmuart_handle_irq;
 	up.port.regshift = 2;
 	up.port.iotype = of_device_is_big_endian(np) ?
@@ -1076,14 +1074,18 @@ static int brcmuart_probe(struct platform_device *pdev)
 		priv->rx_bufs = dma_alloc_coherent(dev,
 						   priv->rx_size,
 						   &priv->rx_addr, GFP_KERNEL);
-		if (!priv->rx_bufs)
+		if (!priv->rx_bufs) {
+			ret = -ENOMEM;
 			goto err;
+		}
 		priv->tx_size = UART_XMIT_SIZE;
 		priv->tx_buf = dma_alloc_coherent(dev,
 						  priv->tx_size,
 						  &priv->tx_addr, GFP_KERNEL);
-		if (!priv->tx_buf)
+		if (!priv->tx_buf) {
+			ret = -ENOMEM;
 			goto err;
+		}
 	}
 
 	ret = serial8250_register_8250_port(&up);
@@ -1097,6 +1099,7 @@ static int brcmuart_probe(struct platform_device *pdev)
 	if (priv->dma_enabled) {
 		dma_irq = platform_get_irq_byname(pdev,  "dma");
 		if (dma_irq < 0) {
+			ret = dma_irq;
 			dev_err(dev, "no IRQ resource info\n");
 			goto err1;
 		}
@@ -1116,7 +1119,7 @@ err1:
 err:
 	brcmuart_free_bufs(dev, priv);
 	brcmuart_arbitration(priv, 0);
-	return -ENODEV;
+	return ret;
 }
 
 static int brcmuart_remove(struct platform_device *pdev)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 1ce193daea7f..01d30f6ed8fb 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -509,11 +509,10 @@ static void __init serial8250_isa_init_ports(void)
 
 		up->ops = &univ8250_driver_ops;
 
-		/*
-		 * ALPHA_KLUDGE_MCR needs to be killed.
-		 */
-		up->mcr_mask = ~ALPHA_KLUDGE_MCR;
-		up->mcr_force = ALPHA_KLUDGE_MCR;
+		if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
+		    (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
+			port->set_mctrl = alpha_jensen_set_mctrl;
+
 		serial8250_set_defaults(up);
 	}
 
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 60f8fffdfd77..e8b5469e9dfa 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1278,7 +1278,7 @@ static int pci_quatech_init(struct pci_dev *dev)
 			outl(inl(base + 0x38) | 0x00002000, base + 0x38);
 			tmp = inl(base + 0x3c);
 			outl(tmp | 0x01000000, base + 0x3c);
-			outl(tmp &= ~0x01000000, base + 0x3c);
+			outl(tmp & ~0x01000000, base + 0x3c);
 		}
 	}
 	return 0;
@@ -1318,89 +1318,6 @@ static int pci_default_setup(struct serial_private *priv,
 
 	return setup_port(priv, port, bar, offset, board->reg_shift);
 }
-static void
-pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
-			       unsigned int quot, unsigned int quot_frac)
-{
-	int scr;
-	int lcr;
-
-	for (scr = 16; scr > 4; scr--) {
-		unsigned int maxrate = port->uartclk / scr;
-		unsigned int divisor = max(maxrate / baud, 1U);
-		int delta = maxrate / divisor - baud;
-
-		if (baud > maxrate + baud / 50)
-			continue;
-
-		if (delta > baud / 50)
-			divisor++;
-
-		if (divisor > 0xffff)
-			continue;
-
-		/* Update delta due to possible divisor change */
-		delta = maxrate / divisor - baud;
-		if (abs(delta) < baud / 50) {
-			lcr = serial_port_in(port, UART_LCR);
-			serial_port_out(port, UART_LCR, lcr | 0x80);
-			serial_port_out(port, UART_DLL, divisor & 0xff);
-			serial_port_out(port, UART_DLM, divisor >> 8 & 0xff);
-			serial_port_out(port, 2, 16 - scr);
-			serial_port_out(port, UART_LCR, lcr);
-			return;
-		}
-	}
-}
-static int pci_pericom_setup(struct serial_private *priv,
-		  const struct pciserial_board *board,
-		  struct uart_8250_port *port, int idx)
-{
-	unsigned int bar, offset = board->first_offset, maxnr;
-
-	bar = FL_GET_BASE(board->flags);
-	if (board->flags & FL_BASE_BARS)
-		bar += idx;
-	else
-		offset += idx * board->uart_offset;
-
-
-	maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
-		(board->reg_shift + 3);
-
-	if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
-		return 1;
-
-	port->port.set_divisor = pericom_do_set_divisor;
-
-	return setup_port(priv, port, bar, offset, board->reg_shift);
-}
-
-static int pci_pericom_setup_four_at_eight(struct serial_private *priv,
-		  const struct pciserial_board *board,
-		  struct uart_8250_port *port, int idx)
-{
-	unsigned int bar, offset = board->first_offset, maxnr;
-
-	bar = FL_GET_BASE(board->flags);
-	if (board->flags & FL_BASE_BARS)
-		bar += idx;
-	else
-		offset += idx * board->uart_offset;
-
-	if (idx==3)
-		offset = 0x38;
-
-	maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
-		(board->reg_shift + 3);
-
-	if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
-		return 1;
-
-	port->port.set_divisor = pericom_do_set_divisor;
-
-	return setup_port(priv, port, bar, offset, board->reg_shift);
-}
 
 static int
 ce4100_serial_setup(struct serial_private *priv,
@@ -1886,42 +1803,6 @@ pci_moxa_setup(struct serial_private *priv,
 #define PCIE_DEVICE_ID_WCH_CH384_8S	0x3853
 #define PCIE_DEVICE_ID_WCH_CH382_2S	0x3253
 
-#define PCI_VENDOR_ID_ACCESIO			0x494f
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_2SDB	0x1051
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM_2S	0x1053
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SDB	0x105C
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4S	0x105E
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM232_2DB	0x1091
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_2	0x1093
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4DB	0x1099
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_4	0x109B
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_2SMDB	0x10D1
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM_2SM	0x10D3
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SMDB	0x10DA
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4SM	0x10DC
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_1	0x1108
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_2	0x1110
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_2	0x1111
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_4	0x1118
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_4	0x1119
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM_2S	0x1152
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S	0x115A
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_2	0x1190
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_2	0x1191
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4	0x1198
-#define PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_4	0x1199
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM_2SM	0x11D0
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM422_4	0x105A
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM485_4	0x105B
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM422_8	0x106A
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM485_8	0x106B
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4	0x1098
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM232_8	0x10A9
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SM	0x10D9
-#define PCI_DEVICE_ID_ACCESIO_PCIE_COM_8SM	0x10E9
-#define PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4SM	0x11D8
-
-
 #define	PCI_DEVICE_ID_MOXA_CP102E	0x1024
 #define	PCI_DEVICE_ID_MOXA_CP102EL	0x1025
 #define	PCI_DEVICE_ID_MOXA_CP104EL_A	0x1045
@@ -2199,16 +2080,6 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 		.exit		= pci_plx9050_exit,
 	},
 	/*
-	 * Pericom (Only 7954 - It have a offset jump for port 4)
-	 */
-	{
-		.vendor		= PCI_VENDOR_ID_PERICOM,
-		.device		= PCI_DEVICE_ID_PERICOM_PI7C9X7954,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= pci_pericom_setup_four_at_eight,
-	},
-	/*
 	 * PLX
 	 */
 	{
@@ -2238,125 +2109,7 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 		.setup		= pci_default_setup,
 		.exit		= pci_plx9050_exit,
 	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SDB,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4S,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4DB,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SMDB,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4SM,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM422_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM485_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SM,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4SM,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup_four_at_eight,
-	},
-	{
-		.vendor     = PCI_VENDOR_ID_ACCESIO,
-		.device     = PCI_ANY_ID,
-		.subvendor  = PCI_ANY_ID,
-		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
-	},	/*
+	/*
 	 * SBS Technologies, Inc., PMC-OCTALPRO 232
 	 */
 	{
@@ -2948,10 +2701,6 @@ enum pci_board_num_t {
 	pbn_wch382_2,
 	pbn_wch384_4,
 	pbn_wch384_8,
-	pbn_pericom_PI7C9X7951,
-	pbn_pericom_PI7C9X7952,
-	pbn_pericom_PI7C9X7954,
-	pbn_pericom_PI7C9X7958,
 	pbn_sunix_pci_1s,
 	pbn_sunix_pci_2s,
 	pbn_sunix_pci_4s,
@@ -3696,33 +3445,6 @@ static struct pciserial_board pci_boards[] = {
 		.uart_offset    = 8,
 		.first_offset   = 0x00,
 	},
-	/*
-	 * Pericom PI7C9X795[1248] Uno/Dual/Quad/Octal UART
-	 */
-	[pbn_pericom_PI7C9X7951] = {
-		.flags          = FL_BASE0,
-		.num_ports      = 1,
-		.base_baud      = 921600,
-		.uart_offset	= 0x8,
-	},
-	[pbn_pericom_PI7C9X7952] = {
-		.flags          = FL_BASE0,
-		.num_ports      = 2,
-		.base_baud      = 921600,
-		.uart_offset	= 0x8,
-	},
-	[pbn_pericom_PI7C9X7954] = {
-		.flags          = FL_BASE0,
-		.num_ports      = 4,
-		.base_baud      = 921600,
-		.uart_offset	= 0x8,
-	},
-	[pbn_pericom_PI7C9X7958] = {
-		.flags          = FL_BASE0,
-		.num_ports      = 8,
-		.base_baud      = 921600,
-		.uart_offset	= 0x8,
-	},
 	[pbn_sunix_pci_1s] = {
 		.num_ports	= 1,
 		.base_baud      = 921600,
@@ -3834,6 +3556,10 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(EXAR, PCI_ANY_ID), },
 	{ PCI_VDEVICE(COMMTECH, PCI_ANY_ID), },
 
+	/* Pericom devices */
+	{ PCI_VDEVICE(PERICOM, PCI_ANY_ID), },
+	{ PCI_VDEVICE(ACCESSIO, PCI_ANY_ID), },
+
 	/* End of the black list */
 	{ }
 };
@@ -5028,127 +4754,6 @@ static const struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 		pbn_b3_8_115200 },
 	/*
-	 * Pericom PI7C9X795[1248] Uno/Dual/Quad/Octal UART
-	 */
-	{   PCI_VENDOR_ID_PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7951,
-		PCI_ANY_ID, PCI_ANY_ID,
-		0,
-		0, pbn_pericom_PI7C9X7951 },
-	{   PCI_VENDOR_ID_PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7952,
-		PCI_ANY_ID, PCI_ANY_ID,
-		0,
-		0, pbn_pericom_PI7C9X7952 },
-	{   PCI_VENDOR_ID_PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7954,
-		PCI_ANY_ID, PCI_ANY_ID,
-		0,
-		0, pbn_pericom_PI7C9X7954 },
-	{   PCI_VENDOR_ID_PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7958,
-		PCI_ANY_ID, PCI_ANY_ID,
-		0,
-		0, pbn_pericom_PI7C9X7958 },
-	/*
-	 * ACCES I/O Products quad
-	 */
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_2SDB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM_2S,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SDB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4S,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM232_2DB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_2,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4DB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_2SMDB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM_2SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SMDB,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_1,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7951 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_2,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_2,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM_2S,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_2,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_2,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM_2SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7952 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM422_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM485_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM422_8,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7958 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM485_8,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7958 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM232_8,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7958 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_COM_8SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7958 },
-	{	PCI_VENDOR_ID_ACCESIO, PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4SM,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_pericom_PI7C9X7954 },
-	/*
 	 * Topic TP560 Data/Fax/Voice 56k modem (reported by Evan Clarke)
 	 */
 	{	PCI_VENDOR_ID_TOPIC, PCI_DEVICE_ID_TOPIC_TP560,
diff --git a/drivers/tty/serial/8250/8250_pericom.c b/drivers/tty/serial/8250/8250_pericom.c
new file mode 100644
index 000000000000..025b055363c3
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pericom.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Driver for Pericom UART */
+
+#include <linux/bits.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/pci.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB	0x1051
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S	0x1053
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4	0x105a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4	0x105b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB	0x105c
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S	0x105e
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8	0x106a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8	0x106b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB	0x1091
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2	0x1093
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4	0x1098
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB	0x1099
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4	0x109b
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8	0x10a9
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB	0x10d1
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM	0x10d3
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM	0x10d9
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB	0x10da
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM	0x10dc
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM	0x10e9
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1	0x1108
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2	0x1110
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2	0x1111
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4	0x1118
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4	0x1119
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S	0x1152
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S	0x115a
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2	0x1190
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2	0x1191
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4	0x1198
+#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4	0x1199
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM	0x11d0
+#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM	0x11d8
+
+struct pericom8250 {
+	void __iomem *virt;
+	unsigned int nr;
+	int line[];
+};
+
+static void pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
+				   unsigned int quot, unsigned int quot_frac)
+{
+	int scr;
+
+	for (scr = 16; scr > 4; scr--) {
+		unsigned int maxrate = port->uartclk / scr;
+		unsigned int divisor = max(maxrate / baud, 1U);
+		int delta = maxrate / divisor - baud;
+
+		if (baud > maxrate + baud / 50)
+			continue;
+
+		if (delta > baud / 50)
+			divisor++;
+
+		if (divisor > 0xffff)
+			continue;
+
+		/* Update delta due to possible divisor change */
+		delta = maxrate / divisor - baud;
+		if (abs(delta) < baud / 50) {
+			struct uart_8250_port *up = up_to_u8250p(port);
+			int lcr = serial_port_in(port, UART_LCR);
+
+			serial_port_out(port, UART_LCR, lcr | 0x80);
+			serial_dl_write(up, divisor);
+			serial_port_out(port, 2, 16 - scr);
+			serial_port_out(port, UART_LCR, lcr);
+			return;
+		}
+	}
+}
+
+static int pericom8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	unsigned int nr, i, bar = 0, maxnr;
+	struct pericom8250 *pericom;
+	struct uart_8250_port uart;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	maxnr = pci_resource_len(pdev, bar) >> 3;
+
+	if (pdev->vendor == PCI_VENDOR_ID_PERICOM)
+		nr = pdev->device & 0x0f;
+	else if (pdev->vendor == PCI_VENDOR_ID_ACCESSIO)
+		nr = BIT(((pdev->device & 0x38) >> 3) - 1);
+	else
+		nr = 1;
+
+	pericom = devm_kzalloc(&pdev->dev, struct_size(pericom, line, nr), GFP_KERNEL);
+	if (!pericom)
+		return -ENOMEM;
+
+	pericom->virt = pcim_iomap(pdev, bar, 0);
+	if (!pericom->virt)
+		return -ENOMEM;
+
+	memset(&uart, 0, sizeof(uart));
+
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = pdev->irq;
+	uart.port.private_data = pericom;
+	uart.port.iotype = UPIO_PORT;
+	uart.port.uartclk = 921600 * 16;
+	uart.port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ | UPF_MAGIC_MULTIPLIER;
+	uart.port.set_divisor = pericom_do_set_divisor;
+	for (i = 0; i < nr && i < maxnr; i++) {
+		unsigned int offset = (i == 3 && nr == 4) ? 0x38 : i * 0x8;
+
+		uart.port.iobase = pci_resource_start(pdev, bar) + offset;
+
+		dev_dbg(&pdev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
+			uart.port.iobase, uart.port.irq, uart.port.iotype);
+
+		pericom->line[i] = serial8250_register_8250_port(&uart);
+		if (pericom->line[i] < 0) {
+			dev_err(&pdev->dev,
+				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
+				uart.port.iobase, uart.port.irq,
+				uart.port.iotype, pericom->line[i]);
+			break;
+		}
+	}
+	pericom->nr = i;
+
+	pci_set_drvdata(pdev, pericom);
+	return 0;
+}
+
+static void pericom8250_remove(struct pci_dev *pdev)
+{
+	struct pericom8250 *pericom = pci_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < pericom->nr; i++)
+		serial8250_unregister_port(pericom->line[i]);
+}
+
+static const struct pci_device_id pericom8250_pci_ids[] = {
+	/*
+	 * Pericom PI7C9X795[1248] Uno/Dual/Quad/Octal UART
+	 * (Only 7954 has an offset jump for port 4)
+	 */
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7951) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7952) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7954) },
+	{ PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7958) },
+
+	/*
+	 * ACCES I/O Products quad
+	 * (Only 7954 has an offset jump for port 4)
+	 */
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM) },
+	{ PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, pericom8250_pci_ids);
+
+static struct pci_driver pericom8250_pci_driver = {
+	.name           = "8250_pericom",
+	.id_table       = pericom8250_pci_ids,
+	.probe          = pericom8250_probe,
+	.remove         = pericom8250_remove,
+};
+module_pci_driver(pericom8250_pci_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Pericom UART driver");
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 46e2079ad1aa..2abb3de11a48 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2026,7 +2026,7 @@ void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	mcr = serial8250_TIOCM_to_MCR(mctrl);
 
-	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
+	mcr |= up->mcr;
 
 	serial8250_out_MCR(up, mcr);
 }
@@ -2056,10 +2056,7 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
 	serial8250_rpm_put(up);
 }
 
-/*
- *	Wait for transmitter & holding register to empty
- */
-static void wait_for_xmitr(struct uart_8250_port *up, int bits)
+static void wait_for_lsr(struct uart_8250_port *up, int bits)
 {
 	unsigned int status, tmout = 10000;
 
@@ -2076,6 +2073,16 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits)
 		udelay(1);
 		touch_nmi_watchdog();
 	}
+}
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_8250_port *up, int bits)
+{
+	unsigned int tmout;
+
+	wait_for_lsr(up, bits);
 
 	/* Wait up to 1s for flow control if necessary */
 	if (up->port.flags & UPF_CONS_FLOW) {
@@ -3092,7 +3099,7 @@ static ssize_t rx_trig_bytes_show(struct device *dev,
 	if (rxtrig_bytes < 0)
 		return rxtrig_bytes;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes);
+	return sysfs_emit(buf, "%d\n", rxtrig_bytes);
 }
 
 static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
@@ -3326,6 +3333,35 @@ static void serial8250_console_restore(struct uart_8250_port *up)
 }
 
 /*
+ * Print a string to the serial port using the device FIFO
+ *
+ * It sends fifosize bytes and then waits for the fifo
+ * to get empty.
+ */
+static void serial8250_console_fifo_write(struct uart_8250_port *up,
+					  const char *s, unsigned int count)
+{
+	int i;
+	const char *end = s + count;
+	unsigned int fifosize = up->port.fifosize;
+	bool cr_sent = false;
+
+	while (s != end) {
+		wait_for_lsr(up, UART_LSR_THRE);
+
+		for (i = 0; i < fifosize && s != end; ++i) {
+			if (*s == '\n' && !cr_sent) {
+				serial_out(up, UART_TX, '\r');
+				cr_sent = true;
+			} else {
+				serial_out(up, UART_TX, *s++);
+				cr_sent = false;
+			}
+		}
+	}
+}
+
+/*
  *	Print a string to the serial port trying not to disturb
  *	any possible real use of the port...
  *
@@ -3340,7 +3376,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 	struct uart_8250_em485 *em485 = up->em485;
 	struct uart_port *port = &up->port;
 	unsigned long flags;
-	unsigned int ier;
+	unsigned int ier, use_fifo;
 	int locked = 1;
 
 	touch_nmi_watchdog();
@@ -3372,7 +3408,20 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 		mdelay(port->rs485.delay_rts_before_send);
 	}
 
-	uart_console_write(port, s, count, serial8250_console_putchar);
+	use_fifo = (up->capabilities & UART_CAP_FIFO) &&
+		port->fifosize > 1 &&
+		(serial_port_in(port, UART_FCR) & UART_FCR_ENABLE_FIFO) &&
+		/*
+		 * After we put a data in the fifo, the controller will send
+		 * it regardless of the CTS state. Therefore, only use fifo
+		 * if we don't use control flow.
+		 */
+		!(up->port.flags & UPF_CONS_FLOW);
+
+	if (likely(use_fifo))
+		serial8250_console_fifo_write(up, s, count);
+	else
+		uart_console_write(port, s, count, serial8250_console_putchar);
 
 	/*
 	 *	Finally, wait for transmitter to become empty
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 8cd11aa63ed5..9d415a38cc71 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -498,6 +498,14 @@ config SERIAL_8250_MID
 	  present on the UART found on Intel Medfield SOC and various other
 	  Intel platforms.
 
+config SERIAL_8250_PERICOM
+	tristate "Support for Pericom and Acces I/O serial ports"
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	help
+	  Selecting this option will enable handling of the extra features
+	  present on the Pericom and Acces I/O UARTs.
+
 config SERIAL_8250_PXA
 	tristate "PXA serial port support"
 	depends on SERIAL_8250
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index b9bcd73c8997..bee908f99ea0 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -5,6 +5,8 @@
 
 obj-$(CONFIG_SERIAL_8250)		+= 8250.o 8250_base.o
 8250-y					:= 8250_core.o
+8250-$(CONFIG_ALPHA_GENERIC)		+= 8250_alpha.o
+8250-$(CONFIG_ALPHA_JENSEN)		+= 8250_alpha.o
 8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o
 8250_base-y				:= 8250_port.o
 8250_base-$(CONFIG_SERIAL_8250_DMA)	+= 8250_dma.o
@@ -36,6 +38,7 @@ obj-$(CONFIG_SERIAL_8250_UNIPHIER)	+= 8250_uniphier.o
 obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
 obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
+obj-$(CONFIG_SERIAL_8250_PERICOM)	+= 8250_pericom.o
 obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
 obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
 obj-$(CONFIG_SERIAL_8250_BCM7271)	+= 8250_bcm7271.o
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index fc543ac97c13..0e5ccb25bdb1 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -263,7 +263,7 @@ config SERIAL_SAMSUNG_UARTS
 
 config SERIAL_SAMSUNG_CONSOLE
 	bool "Support for console on Samsung SoC serial port"
-	depends on SERIAL_SAMSUNG=y
+	depends on SERIAL_SAMSUNG
 	select SERIAL_CORE_CONSOLE
 	select SERIAL_EARLYCON
 	help
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index 23c4e0e79694..37bffe406b18 100644
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -418,8 +418,9 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
 	struct altera_jtaguart_platform_uart *platp =
 			dev_get_platdata(&pdev->dev);
 	struct uart_port *port;
-	struct resource *res_irq, *res_mem;
+	struct resource *res_mem;
 	int i = pdev->id;
+	int irq;
 
 	/* -1 emphasizes that the platform must have one port, no .N suffix */
 	if (i == -1)
@@ -438,9 +439,11 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
 	else
 		return -ENODEV;
 
-	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (res_irq)
-		port->irq = res_irq->start;
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
+		return irq;
+	if (irq > 0)
+		port->irq = irq;
 	else if (platp)
 		port->irq = platp->irq;
 	else
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 7c5f4e966b59..64a352b40197 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -553,7 +553,6 @@ static int altera_uart_probe(struct platform_device *pdev)
 	struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
 	struct uart_port *port;
 	struct resource *res_mem;
-	struct resource *res_irq;
 	int i = pdev->id;
 	int ret;
 
@@ -577,9 +576,11 @@ static int altera_uart_probe(struct platform_device *pdev)
 	else
 		return -EINVAL;
 
-	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (res_irq)
-		port->irq = res_irq->start;
+	ret = platform_get_irq_optional(pdev, 0);
+	if (ret < 0 && ret != -ENXIO)
+		return ret;
+	if (ret > 0)
+		port->irq = ret;
 	else if (platp)
 		port->irq = platp->irq;
 
diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
index e744b953ca34..47654073123d 100644
--- a/drivers/tty/serial/amba-pl010.c
+++ b/drivers/tty/serial/amba-pl010.c
@@ -446,14 +446,11 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
 	if ((termios->c_cflag & CREAD) == 0)
 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
 
-	/* first, disable everything */
 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
 
 	if (UART_ENABLE_MS(port, termios->c_cflag))
 		old_cr |= UART010_CR_MSIE;
 
-	writel(0, uap->port.membase + UART010_CR);
-
 	/* Set baud rate */
 	quot -= 1;
 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 52518a606c06..1f1df46242f9 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -188,38 +188,6 @@ static struct vendor_data vendor_st = {
 	.get_fifosize		= get_fifosize_st,
 };
 
-static const u16 pl011_zte_offsets[REG_ARRAY_SIZE] = {
-	[REG_DR] = ZX_UART011_DR,
-	[REG_FR] = ZX_UART011_FR,
-	[REG_LCRH_RX] = ZX_UART011_LCRH,
-	[REG_LCRH_TX] = ZX_UART011_LCRH,
-	[REG_IBRD] = ZX_UART011_IBRD,
-	[REG_FBRD] = ZX_UART011_FBRD,
-	[REG_CR] = ZX_UART011_CR,
-	[REG_IFLS] = ZX_UART011_IFLS,
-	[REG_IMSC] = ZX_UART011_IMSC,
-	[REG_RIS] = ZX_UART011_RIS,
-	[REG_MIS] = ZX_UART011_MIS,
-	[REG_ICR] = ZX_UART011_ICR,
-	[REG_DMACR] = ZX_UART011_DMACR,
-};
-
-static unsigned int get_fifosize_zte(struct amba_device *dev)
-{
-	return 16;
-}
-
-static struct vendor_data vendor_zte = {
-	.reg_offset		= pl011_zte_offsets,
-	.access_32b		= true,
-	.ifls			= UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
-	.fr_busy		= ZX_UART01x_FR_BUSY,
-	.fr_dsr			= ZX_UART01x_FR_DSR,
-	.fr_cts			= ZX_UART01x_FR_CTS,
-	.fr_ri			= ZX_UART011_FR_RI,
-	.get_fifosize		= get_fifosize_zte,
-};
-
 /* Deals with DMA transactions */
 
 struct pl011_sgbuf {
@@ -262,7 +230,6 @@ struct uart_amba_port {
 	unsigned int		im;		/* interrupt mask */
 	unsigned int		old_status;
 	unsigned int		fifosize;	/* vendor-specific */
-	unsigned int		old_cr;		/* state during shutdown */
 	unsigned int		fixed_baud;	/* vendor-set fixed baud rate */
 	char			type[12];
 	bool			rs485_tx_started;
@@ -1837,8 +1804,8 @@ static int pl011_startup(struct uart_port *port)
 
 	spin_lock_irq(&uap->port.lock);
 
-	/* restore RTS and DTR */
-	cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
+	cr = pl011_read(uap, REG_CR);
+	cr &= UART011_CR_RTS | UART011_CR_DTR;
 	cr |= UART01x_CR_UARTEN | UART011_CR_RXE;
 
 	if (port->rs485.flags & SER_RS485_ENABLED) {
@@ -1915,7 +1882,6 @@ static void pl011_disable_uart(struct uart_amba_port *uap)
 	uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
 	spin_lock_irq(&uap->port.lock);
 	cr = pl011_read(uap, REG_CR);
-	uap->old_cr = cr;
 	cr &= UART011_CR_RTS | UART011_CR_DTR;
 	cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
 	pl011_write(cr, uap, REG_CR);
@@ -2105,9 +2071,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (port->rs485.flags & SER_RS485_ENABLED)
 		termios->c_cflag &= ~CRTSCTS;
 
-	/* first, disable everything */
 	old_cr = pl011_read(uap, REG_CR);
-	pl011_write(0, uap, REG_CR);
 
 	if (termios->c_cflag & CRTSCTS) {
 		if (old_cr & UART011_CR_RTS)
@@ -2184,31 +2148,12 @@ static const char *pl011_type(struct uart_port *port)
 }
 
 /*
- * Release the memory region(s) being used by 'port'
- */
-static void pl011_release_port(struct uart_port *port)
-{
-	release_mem_region(port->mapbase, SZ_4K);
-}
-
-/*
- * Request the memory region(s) being used by 'port'
- */
-static int pl011_request_port(struct uart_port *port)
-{
-	return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
-			!= NULL ? 0 : -EBUSY;
-}
-
-/*
  * Configure/autoconfigure the port.
  */
 static void pl011_config_port(struct uart_port *port, int flags)
 {
-	if (flags & UART_CONFIG_TYPE) {
+	if (flags & UART_CONFIG_TYPE)
 		port->type = PORT_AMBA;
-		pl011_request_port(port);
-	}
 }
 
 /*
@@ -2223,6 +2168,8 @@ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
 		ret = -EINVAL;
 	if (ser->baud_base < 9600)
 		ret = -EINVAL;
+	if (port->mapbase != (unsigned long) ser->iomem_base)
+		ret = -EINVAL;
 	return ret;
 }
 
@@ -2275,8 +2222,6 @@ static const struct uart_ops amba_pl011_pops = {
 	.flush_buffer	= pl011_dma_flush_buffer,
 	.set_termios	= pl011_set_termios,
 	.type		= pl011_type,
-	.release_port	= pl011_release_port,
-	.request_port	= pl011_request_port,
 	.config_port	= pl011_config_port,
 	.verify_port	= pl011_verify_port,
 #ifdef CONFIG_CONSOLE_POLL
@@ -2306,8 +2251,6 @@ static const struct uart_ops sbsa_uart_pops = {
 	.shutdown	= sbsa_uart_shutdown,
 	.set_termios	= sbsa_uart_set_termios,
 	.type		= pl011_type,
-	.release_port	= pl011_release_port,
-	.request_port	= pl011_request_port,
 	.config_port	= pl011_config_port,
 	.verify_port	= pl011_verify_port,
 #ifdef CONFIG_CONSOLE_POLL
@@ -2754,7 +2697,6 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
 
 	index = pl011_probe_dt_alias(index, dev);
 
-	uap->old_cr = 0;
 	uap->port.dev = dev;
 	uap->port.mapbase = mmiobase->start;
 	uap->port.membase = base;
@@ -2975,11 +2917,6 @@ static const struct amba_id pl011_ids[] = {
 		.mask	= 0x00ffffff,
 		.data	= &vendor_st,
 	},
-	{
-		.id	= AMBA_LINUX_ID(0x00, 0x1, 0xffe),
-		.mask	= 0x00ffffff,
-		.data	= &vendor_zte,
-	},
 	{ 0, 0 },
 };
 
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index 4379ca4842ae..8cabe50c4a33 100644
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -707,11 +707,11 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	struct ar933x_uart_port *up;
 	struct uart_port *port;
 	struct resource *mem_res;
-	struct resource *irq_res;
 	struct device_node *np;
 	unsigned int baud;
 	int id;
 	int ret;
+	int irq;
 
 	np = pdev->dev.of_node;
 	if (IS_ENABLED(CONFIG_OF) && np) {
@@ -730,11 +730,9 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	if (id >= CONFIG_SERIAL_AR933X_NR_UARTS)
 		return -EINVAL;
 
-	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq_res) {
-		dev_err(&pdev->dev, "no IRQ resource\n");
-		return -EINVAL;
-	}
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
 			  GFP_KERNEL);
@@ -766,7 +764,7 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 
 	port->mapbase = mem_res->start;
 	port->line = id;
-	port->irq = irq_res->start;
+	port->irq = irq;
 	port->dev = &pdev->dev;
 	port->type = PORT_AR933X;
 	port->iotype = UPIO_MEM32;
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 2c99a47a2535..c370eddc651b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1004,6 +1004,13 @@ static void atmel_tx_dma(struct uart_port *port)
 		desc->callback = atmel_complete_tx_dma;
 		desc->callback_param = atmel_port;
 		atmel_port->cookie_tx = dmaengine_submit(desc);
+		if (dma_submit_error(atmel_port->cookie_tx)) {
+			dev_err(port->dev, "dma_submit_error %d\n",
+				atmel_port->cookie_tx);
+			return;
+		}
+
+		dma_async_issue_pending(chan);
 	}
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -1258,6 +1265,13 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 	desc->callback_param = port;
 	atmel_port->desc_rx = desc;
 	atmel_port->cookie_rx = dmaengine_submit(desc);
+	if (dma_submit_error(atmel_port->cookie_rx)) {
+		dev_err(port->dev, "dma_submit_error %d\n",
+			atmel_port->cookie_rx);
+		goto chan_err;
+	}
+
+	dma_async_issue_pending(atmel_port->chan_rx);
 
 	return 0;
 
@@ -2479,7 +2493,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
 	port->fifosize		= 1;
 	port->dev		= &pdev->dev;
 	port->mapbase		= mpdev->resource[0].start;
-	port->irq		= mpdev->resource[1].start;
+	port->irq		= platform_get_irq(mpdev, 0);
 	port->rs485_config	= atmel_config_rs485;
 	port->iso7816_config	= atmel_config_iso7816;
 	port->membase		= NULL;
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
index 5fb0e84f7fd1..6471a54b616b 100644
--- a/drivers/tty/serial/bcm63xx_uart.c
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -804,7 +804,7 @@ static struct uart_driver bcm_uart_driver = {
  */
 static int bcm_uart_probe(struct platform_device *pdev)
 {
-	struct resource *res_mem, *res_irq;
+	struct resource *res_mem;
 	struct uart_port *port;
 	struct clk *clk;
 	int ret;
@@ -833,9 +833,10 @@ static int bcm_uart_probe(struct platform_device *pdev)
 	if (IS_ERR(port->membase))
 		return PTR_ERR(port->membase);
 
-	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!res_irq)
-		return -ENODEV;
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	port->irq = ret;
 
 	clk = clk_get(&pdev->dev, "refclk");
 	if (IS_ERR(clk) && pdev->dev.of_node)
@@ -845,7 +846,6 @@ static int bcm_uart_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	port->iotype = UPIO_MEM;
-	port->irq = res_irq->start;
 	port->ops = &bcm_uart_ops;
 	port->flags = UPF_BOOT_AUTOCONF;
 	port->dev = &pdev->dev;
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index ac5112def40d..ce3e26144689 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -247,6 +247,7 @@ enum lpuart_type {
 	LS1028A_LPUART,
 	IMX7ULP_LPUART,
 	IMX8QXP_LPUART,
+	IMXRT1050_LPUART,
 };
 
 struct lpuart_port {
@@ -310,6 +311,11 @@ static struct lpuart_soc_data imx8qxp_data = {
 	.iotype = UPIO_MEM32,
 	.reg_off = IMX_REG_OFF,
 };
+static struct lpuart_soc_data imxrt1050_data = {
+	.devtype = IMXRT1050_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+};
 
 static const struct of_device_id lpuart_dt_ids[] = {
 	{ .compatible = "fsl,vf610-lpuart",	.data = &vf_data, },
@@ -317,6 +323,7 @@ static const struct of_device_id lpuart_dt_ids[] = {
 	{ .compatible = "fsl,ls1028a-lpuart",	.data = &ls1028a_data, },
 	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx7ulp_data, },
 	{ .compatible = "fsl,imx8qxp-lpuart",	.data = &imx8qxp_data, },
+	{ .compatible = "fsl,imxrt1050-lpuart",	.data = &imxrt1050_data},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
@@ -1793,8 +1800,8 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport)
 	}
 
 	if (sport->lpuart_dma_tx_use) {
-		if (wait_event_interruptible(sport->dma_wait,
-			!sport->dma_tx_in_progress) != false) {
+		if (wait_event_interruptible_timeout(sport->dma_wait,
+			!sport->dma_tx_in_progress, msecs_to_jiffies(300)) <= 0) {
 			sport->dma_tx_in_progress = false;
 			dmaengine_terminate_all(sport->dma_tx_chan);
 		}
@@ -2626,6 +2633,7 @@ OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup
 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imxrt1050-lpuart", lpuart32_imx_early_console_setup);
 EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
 EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
 
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 90f82e6c54e4..df8a0c8b8b29 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -486,18 +486,21 @@ static void imx_uart_stop_tx(struct uart_port *port)
 static void imx_uart_stop_rx(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
-	u32 ucr1, ucr2;
+	u32 ucr1, ucr2, ucr4;
 
 	ucr1 = imx_uart_readl(sport, UCR1);
 	ucr2 = imx_uart_readl(sport, UCR2);
+	ucr4 = imx_uart_readl(sport, UCR4);
 
 	if (sport->dma_is_enabled) {
 		ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
 	} else {
 		ucr1 &= ~UCR1_RRDYEN;
 		ucr2 &= ~UCR2_ATEN;
+		ucr4 &= ~UCR4_OREN;
 	}
 	imx_uart_writel(sport, ucr1, UCR1);
+	imx_uart_writel(sport, ucr4, UCR4);
 
 	ucr2 &= ~UCR2_RXEN;
 	imx_uart_writel(sport, ucr2, UCR2);
@@ -1544,7 +1547,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 	imx_uart_writel(sport, ucr1, UCR1);
 
 	ucr4 = imx_uart_readl(sport, UCR4);
-	ucr4 &= ~(UCR4_OREN | UCR4_TCEN);
+	ucr4 &= ~UCR4_TCEN;
 	imx_uart_writel(sport, ucr4, UCR4);
 
 	spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -2482,10 +2485,12 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 
 	if (sport->have_rtscts) {
 		u32 ucr1 = imx_uart_readl(sport, UCR1);
-		if (on)
+		if (on) {
+			imx_uart_writel(sport, USR1_RTSD, USR1);
 			ucr1 |= UCR1_RTSDEN;
-		else
+		} else {
 			ucr1 &= ~UCR1_RTSDEN;
+		}
 		imx_uart_writel(sport, ucr1, UCR1);
 	}
 }
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 497b334bc845..3e324d3f0a6d 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -16,8 +16,6 @@
 #include <linux/ioport.h>
 #include <linux/lantiq.h>
 #include <linux/module.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/serial.h>
 #include <linux/serial_core.h>
@@ -728,19 +726,23 @@ static struct uart_driver lqasc_reg = {
 static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
 {
 	struct uart_port *port = &ltq_port->port;
-	struct resource irqres[3];
-	int ret;
-
-	ret = of_irq_to_resource_table(dev->of_node, irqres, 3);
-	if (ret != 3) {
-		dev_err(dev,
-			"failed to get IRQs for serial port\n");
-		return -ENODEV;
-	}
-	ltq_port->tx_irq = irqres[0].start;
-	ltq_port->rx_irq = irqres[1].start;
-	ltq_port->err_irq = irqres[2].start;
-	port->irq = irqres[0].start;
+	struct platform_device *pdev = to_platform_device(dev);
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	ltq_port->tx_irq = irq;
+	irq = platform_get_irq(pdev, 1);
+	if (irq < 0)
+		return irq;
+	ltq_port->rx_irq = irq;
+	irq = platform_get_irq(pdev, 2);
+	if (irq < 0)
+		return irq;
+	ltq_port->err_irq = irq;
+
+	port->irq = ltq_port->tx_irq;
 
 	return 0;
 }
@@ -793,7 +795,7 @@ static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
 	struct uart_port *port = &ltq_port->port;
 	int ret;
 
-	ret = of_irq_get(dev->of_node, 0);
+	ret = platform_get_irq(to_platform_device(dev), 0);
 	if (ret < 0) {
 		dev_err(dev, "failed to fetch IRQ for serial port\n");
 		return ret;
diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
index 2941659e5274..7f74bf7bdcff 100644
--- a/drivers/tty/serial/liteuart.c
+++ b/drivers/tty/serial/liteuart.c
@@ -436,4 +436,4 @@ module_exit(liteuart_exit);
 MODULE_AUTHOR("Antmicro <www.antmicro.com>");
 MODULE_DESCRIPTION("LiteUART serial driver");
 MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform: liteuart");
+MODULE_ALIAS("platform:liteuart");
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c
index b199d7859961..07c4161eb4cc 100644
--- a/drivers/tty/serial/lpc32xx_hs.c
+++ b/drivers/tty/serial/lpc32xx_hs.c
@@ -341,7 +341,7 @@ static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
 		       LPC32XX_HSUART_IIR(port->membase));
 		port->icount.overrun++;
 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
-		tty_schedule_flip(tport);
+		tty_flip_buffer_push(tport);
 	}
 
 	/* Data received? */
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index efee3935917f..45e00d928253 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -622,10 +622,7 @@ meson_serial_early_console_setup(struct earlycon_device *device, const char *opt
 	device->con->write = meson_serial_early_console_write;
 	return 0;
 }
-/* Legacy bindings, should be removed when no more used */
-OF_EARLYCON_DECLARE(meson, "amlogic,meson-uart",
-		    meson_serial_early_console_setup);
-/* Stable bindings */
+
 OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart",
 		    meson_serial_early_console_setup);
 
@@ -668,25 +665,6 @@ static inline struct clk *meson_uart_probe_clock(struct device *dev,
 	return clk;
 }
 
-/*
- * This function gets clocks in the legacy non-stable DT bindings.
- * This code will be remove once all the platforms switch to the
- * new DT bindings.
- */
-static int meson_uart_probe_clocks_legacy(struct platform_device *pdev,
-					  struct uart_port *port)
-{
-	struct clk *clk = NULL;
-
-	clk = meson_uart_probe_clock(&pdev->dev, NULL);
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
-
-	port->uartclk = clk_get_rate(clk);
-
-	return 0;
-}
-
 static int meson_uart_probe_clocks(struct platform_device *pdev,
 				   struct uart_port *port)
 {
@@ -713,10 +691,11 @@ static int meson_uart_probe_clocks(struct platform_device *pdev,
 
 static int meson_uart_probe(struct platform_device *pdev)
 {
-	struct resource *res_mem, *res_irq;
+	struct resource *res_mem;
 	struct uart_port *port;
 	u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
 	int ret = 0;
+	int irq;
 
 	if (pdev->dev.of_node)
 		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -739,9 +718,9 @@ static int meson_uart_probe(struct platform_device *pdev)
 	if (!res_mem)
 		return -ENODEV;
 
-	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!res_irq)
-		return -ENODEV;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
 
@@ -754,19 +733,14 @@ static int meson_uart_probe(struct platform_device *pdev)
 	if (!port)
 		return -ENOMEM;
 
-	/* Use legacy way until all platforms switch to new bindings */
-	if (of_device_is_compatible(pdev->dev.of_node, "amlogic,meson-uart"))
-		ret = meson_uart_probe_clocks_legacy(pdev, port);
-	else
-		ret = meson_uart_probe_clocks(pdev, port);
-
+	ret = meson_uart_probe_clocks(pdev, port);
 	if (ret)
 		return ret;
 
 	port->iotype = UPIO_MEM;
 	port->mapbase = res_mem->start;
 	port->mapsize = resource_size(res_mem);
-	port->irq = res_irq->start;
+	port->irq = irq;
 	port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
 	port->dev = &pdev->dev;
@@ -804,9 +778,6 @@ static int meson_uart_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id meson_uart_dt_match[] = {
-	/* Legacy bindings, should be removed when no more used */
-	{ .compatible = "amlogic,meson-uart" },
-	/* Stable bindings */
 	{ .compatible = "amlogic,meson6-uart" },
 	{ .compatible = "amlogic,meson8-uart" },
 	{ .compatible = "amlogic,meson8b-uart" },
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 12ce150b0ad4..5359236b32d6 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1702,17 +1702,21 @@ extern struct platform_device scc_a_pdev, scc_b_pdev;
 
 static int __init pmz_init_port(struct uart_pmac_port *uap)
 {
-	struct resource *r_ports, *r_irq;
+	struct resource *r_ports;
+	int irq;
 
 	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
-	r_irq = platform_get_resource(uap->pdev, IORESOURCE_IRQ, 0);
-	if (!r_ports || !r_irq)
+	if (!r_ports)
 		return -ENODEV;
 
+	irq = platform_get_irq(uap->pdev, 0);
+	if (irq < 0)
+		return irq;
+
 	uap->port.mapbase  = r_ports->start;
 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
 	uap->port.iotype   = UPIO_MEM;
-	uap->port.irq      = r_irq->start;
+	uap->port.irq      = irq;
 	uap->port.uartclk  = ZS_CLOCK;
 	uap->port.fifosize = 1;
 	uap->port.ops      = &pmz_pops;
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 41319ef96fa6..30b099746a75 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -842,14 +842,18 @@ static int serial_pxa_probe_dt(struct platform_device *pdev,
 static int serial_pxa_probe(struct platform_device *dev)
 {
 	struct uart_pxa_port *sport;
-	struct resource *mmres, *irqres;
+	struct resource *mmres;
 	int ret;
+	int irq;
 
 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
-	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
-	if (!mmres || !irqres)
+	if (!mmres)
 		return -ENODEV;
 
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0)
+		return irq;
+
 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
 	if (!sport)
 		return -ENOMEM;
@@ -869,7 +873,7 @@ static int serial_pxa_probe(struct platform_device *dev)
 	sport->port.type = PORT_PXA;
 	sport->port.iotype = UPIO_MEM;
 	sport->port.mapbase = mmres->start;
-	sport->port.irq = irqres->start;
+	sport->port.irq = irq;
 	sport->port.fifosize = 64;
 	sport->port.ops = &serial_pxa_pops;
 	sport->port.dev = &dev->dev;
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index ca084c10d0bb..d002a4e48ed9 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -65,7 +65,6 @@ enum s3c24xx_port_type {
 struct s3c24xx_uart_info {
 	char			*name;
 	enum s3c24xx_port_type	type;
-	bool			has_usi;
 	unsigned int		port_type;
 	unsigned int		fifosize;
 	unsigned long		rx_fifomask;
@@ -1357,28 +1356,6 @@ static int apple_s5l_serial_startup(struct uart_port *port)
 	return ret;
 }
 
-static void exynos_usi_init(struct uart_port *port)
-{
-	struct s3c24xx_uart_port *ourport = to_ourport(port);
-	struct s3c24xx_uart_info *info = ourport->info;
-	unsigned int val;
-
-	if (!info->has_usi)
-		return;
-
-	/* Clear the software reset of USI block (it's set at startup) */
-	val = rd_regl(port, USI_CON);
-	val &= ~USI_CON_RESET_MASK;
-	wr_regl(port, USI_CON, val);
-	udelay(1);
-
-	/* Continuously provide the clock to USI IP w/o gating (for Rx mode) */
-	val = rd_regl(port, USI_OPTION);
-	val &= ~USI_OPTION_HWACG_MASK;
-	val |= USI_OPTION_HWACG_CLKREQ_ON;
-	wr_regl(port, USI_OPTION, val);
-}
-
 /* power power management control */
 
 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
@@ -1405,8 +1382,6 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
 
 		if (!IS_ERR(ourport->baudclk))
 			clk_prepare_enable(ourport->baudclk);
-
-		exynos_usi_init(port);
 		break;
 	default:
 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
@@ -1740,15 +1715,21 @@ s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
 
 static struct console s3c24xx_serial_console;
 
-static int __init s3c24xx_serial_console_init(void)
+static void __init s3c24xx_serial_register_console(void)
 {
 	register_console(&s3c24xx_serial_console);
-	return 0;
 }
-console_initcall(s3c24xx_serial_console_init);
+
+static void s3c24xx_serial_unregister_console(void)
+{
+	if (s3c24xx_serial_console.flags & CON_ENABLED)
+		unregister_console(&s3c24xx_serial_console);
+}
 
 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
 #else
+static inline void s3c24xx_serial_register_console(void) { }
+static inline void s3c24xx_serial_unregister_console(void) { }
 #define S3C24XX_SERIAL_CONSOLE NULL
 #endif
 
@@ -2130,8 +2111,6 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	if (ret)
 		pr_warn("uart: failed to enable baudclk\n");
 
-	exynos_usi_init(port);
-
 	/* Keep all interrupts masked and cleared */
 	switch (ourport->info->type) {
 	case TYPE_S3C6400:
@@ -2521,7 +2500,8 @@ s3c24xx_serial_console_write(struct console *co, const char *s,
 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
 }
 
-static void __init
+/* Shouldn't be __init, as it can be instantiated from other module */
+static void
 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
 			   int *parity, int *bits)
 {
@@ -2584,7 +2564,8 @@ s3c24xx_serial_get_options(struct uart_port *port, int *baud,
 	}
 }
 
-static int __init
+/* Shouldn't be __init, as it can be instantiated from other module */
+static int
 s3c24xx_serial_console_setup(struct console *co, char *options)
 {
 	struct uart_port *port;
@@ -2780,11 +2761,10 @@ static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 #endif
 
 #if defined(CONFIG_ARCH_EXYNOS)
-#define EXYNOS_COMMON_SERIAL_DRV_DATA(_has_usi)			\
+#define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
 	.info = &(struct s3c24xx_uart_info) {			\
 		.name		= "Samsung Exynos UART",	\
 		.type		= TYPE_S3C6400,			\
-		.has_usi	= _has_usi,			\
 		.port_type	= PORT_S3C6400,			\
 		.has_divslot	= 1,				\
 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
@@ -2805,17 +2785,17 @@ static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 	}							\
 
 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 256, 64, 16, 16 },
 };
 
 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 64, 256, 16, 256 },
 };
 
 static struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(true),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 256, 64, 64, 64 },
 };
 
@@ -2926,7 +2906,29 @@ static struct platform_driver samsung_serial_driver = {
 	},
 };
 
-module_platform_driver(samsung_serial_driver);
+static int __init samsung_serial_init(void)
+{
+	int ret;
+
+	s3c24xx_serial_register_console();
+
+	ret = platform_driver_register(&samsung_serial_driver);
+	if (ret) {
+		s3c24xx_serial_unregister_console();
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit samsung_serial_exit(void)
+{
+	platform_driver_unregister(&samsung_serial_driver);
+	s3c24xx_serial_unregister_console();
+}
+
+module_init(samsung_serial_init);
+module_exit(samsung_serial_exit);
 
 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
 /*
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 61e3dd0222af..dc40c4155356 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -162,7 +162,7 @@ static void uart_port_dtr_rts(struct uart_port *uport, int raise)
 	int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
 
 	if (raise) {
-		if (rs485_on && !RTS_after_send) {
+		if (rs485_on && RTS_after_send) {
 			uart_set_mctrl(uport, TIOCM_DTR);
 			uart_clear_mctrl(uport, TIOCM_RTS);
 		} else {
@@ -171,7 +171,7 @@ static void uart_port_dtr_rts(struct uart_port *uport, int raise)
 	} else {
 		unsigned int clear = TIOCM_DTR;
 
-		clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
+		clear |= (!rs485_on || RTS_after_send) ? TIOCM_RTS : 0;
 		uart_clear_mctrl(uport, clear);
 	}
 }
@@ -1701,17 +1701,13 @@ static void uart_port_shutdown(struct tty_port *port)
 	 */
 	wake_up_interruptible(&port->delta_msr_wait);
 
-	/*
-	 * Free the IRQ and disable the port.
-	 */
-	if (uport)
+	if (uport) {
+		/* Free the IRQ and disable the port. */
 		uport->ops->shutdown(uport);
 
-	/*
-	 * Ensure that the IRQ handler isn't running on another CPU.
-	 */
-	if (uport)
+		/* Ensure that the IRQ handler isn't running on another CPU. */
 		synchronize_irq(uport->irq);
+	}
 }
 
 static int uart_carrier_raised(struct tty_port *port)
@@ -2393,7 +2389,8 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 * We probably don't need a spinlock around this, but
 		 */
 		spin_lock_irqsave(&port->lock, flags);
-		port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
+		port->mctrl &= TIOCM_DTR;
+		port->ops->set_mctrl(port, port->mctrl);
 		spin_unlock_irqrestore(&port->lock, flags);
 
 		/*
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 89ee43061d3a..968967d722d4 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -37,6 +37,7 @@
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/scatterlist.h>
 #include <linux/serial.h>
 #include <linux/serial_sci.h>
@@ -895,11 +896,9 @@ static void sci_receive_chars(struct uart_port *port)
 				if (status & SCxSR_FER(port)) {
 					flag = TTY_FRAME;
 					port->icount.frame++;
-					dev_notice(port->dev, "frame error\n");
 				} else if (status & SCxSR_PER(port)) {
 					flag = TTY_PARITY;
 					port->icount.parity++;
-					dev_notice(port->dev, "parity error\n");
 				} else
 					flag = TTY_NORMAL;
 
@@ -939,8 +938,6 @@ static int sci_handle_errors(struct uart_port *port)
 		/* overrun error */
 		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 			copied++;
-
-		dev_notice(port->dev, "overrun error\n");
 	}
 
 	if (status & SCxSR_FER(port)) {
@@ -949,8 +946,6 @@ static int sci_handle_errors(struct uart_port *port)
 
 		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
 			copied++;
-
-		dev_notice(port->dev, "frame error\n");
 	}
 
 	if (status & SCxSR_PER(port)) {
@@ -959,8 +954,6 @@ static int sci_handle_errors(struct uart_port *port)
 
 		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
 			copied++;
-
-		dev_notice(port->dev, "parity error\n");
 	}
 
 	if (copied)
@@ -990,8 +983,6 @@ static int sci_handle_fifo_overrun(struct uart_port *port)
 
 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 		tty_flip_buffer_push(tport);
-
-		dev_dbg(port->dev, "overrun error\n");
 		copied++;
 	}
 
@@ -1013,8 +1004,6 @@ static int sci_handle_breaks(struct uart_port *port)
 		/* Notify of BREAK */
 		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
 			copied++;
-
-		dev_dbg(port->dev, "BREAK detected\n");
 	}
 
 	if (copied)
@@ -2778,44 +2767,29 @@ static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
 		clk_names[SCI_SCK] = "hsck";
 
 	for (i = 0; i < SCI_NUM_CLKS; i++) {
-		clk = devm_clk_get(dev, clk_names[i]);
-		if (PTR_ERR(clk) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
-
-		if (IS_ERR(clk) && i == SCI_FCK) {
-			/*
-			 * "fck" used to be called "sci_ick", and we need to
-			 * maintain DT backward compatibility.
-			 */
-			clk = devm_clk_get(dev, "sci_ick");
-			if (PTR_ERR(clk) == -EPROBE_DEFER)
-				return -EPROBE_DEFER;
-
-			if (!IS_ERR(clk))
-				goto found;
+		clk = devm_clk_get_optional(dev, clk_names[i]);
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
 
+		if (!clk && i == SCI_FCK) {
 			/*
 			 * Not all SH platforms declare a clock lookup entry
 			 * for SCI devices, in which case we need to get the
 			 * global "peripheral_clk" clock.
 			 */
 			clk = devm_clk_get(dev, "peripheral_clk");
-			if (!IS_ERR(clk))
-				goto found;
-
-			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
-				PTR_ERR(clk));
-			return PTR_ERR(clk);
+			if (IS_ERR(clk))
+				return dev_err_probe(dev, PTR_ERR(clk),
+						     "failed to get %s\n",
+						     clk_names[i]);
 		}
 
-found:
-		if (IS_ERR(clk))
-			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
-				PTR_ERR(clk));
+		if (!clk)
+			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
 		else
 			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
 				clk, clk_get_rate(clk));
-		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
+		sci_port->clks[i] = clk;
 	}
 	return 0;
 }
@@ -3180,6 +3154,9 @@ static const struct of_device_id of_sci_match[] = {
 	}, {
 		.compatible = "renesas,rcar-gen3-scif",
 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
+	}, {
+		.compatible = "renesas,rcar-gen4-scif",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
 	},
 	/* Generic types */
 	{
@@ -3203,23 +3180,47 @@ static const struct of_device_id of_sci_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_sci_match);
 
+static void sci_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 					  unsigned int *dev_id)
 {
 	struct device_node *np = pdev->dev.of_node;
+	struct reset_control *rstc;
 	struct plat_sci_port *p;
 	struct sci_port *sp;
 	const void *data;
-	int id;
+	int id, ret;
 
 	if (!IS_ENABLED(CONFIG_OF) || !np)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
 	data = of_device_get_match_data(&pdev->dev);
 
+	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(rstc))
+		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
+					     "failed to get reset ctrl\n"));
+
+	ret = reset_control_deassert(rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
+			ret);
+		return ERR_PTR(ret);
+	}
+
 	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
 	if (!p)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	/* Get the line number from the aliases node. */
 	id = of_alias_get_id(np, "serial");
@@ -3227,11 +3228,11 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 		id = ffz(sci_ports_in_use);
 	if (id < 0) {
 		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 	if (id >= ARRAY_SIZE(sci_ports)) {
 		dev_err(&pdev->dev, "serial%d out of range\n", id);
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	sp = &sci_ports[id];
@@ -3318,8 +3319,8 @@ static int sci_probe(struct platform_device *dev)
 
 	if (dev->dev.of_node) {
 		p = sci_parse_dt(dev, &dev_id);
-		if (p == NULL)
-			return -EINVAL;
+		if (IS_ERR(p))
+			return PTR_ERR(p);
 	} else {
 		p = dev->dev.platform_data;
 		if (p == NULL) {
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 3244e7f6818c..1f89ab0e49ac 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -365,6 +365,31 @@ static unsigned int stm32_usart_receive_chars(struct uart_port *port, bool force
 	return size;
 }
 
+static void stm32_usart_tx_dma_terminate(struct stm32_port *stm32_port)
+{
+	dmaengine_terminate_async(stm32_port->tx_ch);
+	stm32_port->tx_dma_busy = false;
+}
+
+static bool stm32_usart_tx_dma_started(struct stm32_port *stm32_port)
+{
+	/*
+	 * We cannot use the function "dmaengine_tx_status" to know the
+	 * status of DMA. This function does not show if the "dma complete"
+	 * callback of the DMA transaction has been called. So we prefer
+	 * to use "tx_dma_busy" flag to prevent dual DMA transaction at the
+	 * same time.
+	 */
+	return stm32_port->tx_dma_busy;
+}
+
+static bool stm32_usart_tx_dma_enabled(struct stm32_port *stm32_port)
+{
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	return !!(readl_relaxed(stm32_port->port.membase + ofs->cr3) & USART_CR3_DMAT);
+}
+
 static void stm32_usart_tx_dma_complete(void *arg)
 {
 	struct uart_port *port = arg;
@@ -372,9 +397,8 @@ static void stm32_usart_tx_dma_complete(void *arg)
 	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 	unsigned long flags;
 
-	dmaengine_terminate_async(stm32port->tx_ch);
 	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
-	stm32port->tx_dma_busy = false;
+	stm32_usart_tx_dma_terminate(stm32port);
 
 	/* Let's see if we have pending data to send */
 	spin_lock_irqsave(&port->lock, flags);
@@ -428,10 +452,8 @@ static void stm32_usart_transmit_chars_pio(struct uart_port *port)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct circ_buf *xmit = &port->state->xmit;
 
-	if (stm32_port->tx_dma_busy) {
+	if (stm32_usart_tx_dma_enabled(stm32_port))
 		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
-		stm32_port->tx_dma_busy = false;
-	}
 
 	while (!uart_circ_empty(xmit)) {
 		/* Check that TDR is empty before filling FIFO */
@@ -455,12 +477,13 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port)
 	const struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
 	struct circ_buf *xmit = &port->state->xmit;
 	struct dma_async_tx_descriptor *desc = NULL;
-	unsigned int count, i;
+	unsigned int count;
 
-	if (stm32port->tx_dma_busy)
+	if (stm32_usart_tx_dma_started(stm32port)) {
+		if (!stm32_usart_tx_dma_enabled(stm32port))
+			stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 		return;
-
-	stm32port->tx_dma_busy = true;
+	}
 
 	count = uart_circ_chars_pending(xmit);
 
@@ -491,13 +514,21 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port)
 	if (!desc)
 		goto fallback_err;
 
+	/*
+	 * Set "tx_dma_busy" flag. This flag will be released when
+	 * dmaengine_terminate_async will be called. This flag helps
+	 * transmit_chars_dma not to start another DMA transaction
+	 * if the callback of the previous is not yet called.
+	 */
+	stm32port->tx_dma_busy = true;
+
 	desc->callback = stm32_usart_tx_dma_complete;
 	desc->callback_param = port;
 
 	/* Push current DMA TX transaction in the pending queue */
 	if (dma_submit_error(dmaengine_submit(desc))) {
 		/* dma no yet started, safe to free resources */
-		dmaengine_terminate_async(stm32port->tx_ch);
+		stm32_usart_tx_dma_terminate(stm32port);
 		goto fallback_err;
 	}
 
@@ -511,8 +542,7 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port)
 	return;
 
 fallback_err:
-	for (i = count; i > 0; i--)
-		stm32_usart_transmit_chars_pio(port);
+	stm32_usart_transmit_chars_pio(port);
 }
 
 static void stm32_usart_transmit_chars(struct uart_port *port)
@@ -522,12 +552,13 @@ static void stm32_usart_transmit_chars(struct uart_port *port)
 	struct circ_buf *xmit = &port->state->xmit;
 
 	if (port->x_char) {
-		if (stm32_port->tx_dma_busy)
+		if (stm32_usart_tx_dma_started(stm32_port) &&
+		    stm32_usart_tx_dma_enabled(stm32_port))
 			stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 		writel_relaxed(port->x_char, port->membase + ofs->tdr);
 		port->x_char = 0;
 		port->icount.tx++;
-		if (stm32_port->tx_dma_busy)
+		if (stm32_usart_tx_dma_started(stm32_port))
 			stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 		return;
 	}
@@ -675,8 +706,11 @@ static void stm32_usart_stop_tx(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct serial_rs485 *rs485conf = &port->rs485;
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
 	stm32_usart_tx_interrupt_disable(port);
+	if (stm32_usart_tx_dma_started(stm32_port) && stm32_usart_tx_dma_enabled(stm32_port))
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
@@ -719,9 +753,8 @@ static void stm32_usart_flush_buffer(struct uart_port *port)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
 	if (stm32_port->tx_ch) {
-		dmaengine_terminate_async(stm32_port->tx_ch);
+		stm32_usart_tx_dma_terminate(stm32_port);
 		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
-		stm32_port->tx_dma_busy = false;
 	}
 }
 
@@ -883,6 +916,12 @@ static void stm32_usart_shutdown(struct uart_port *port)
 	u32 val, isr;
 	int ret;
 
+	if (stm32_usart_tx_dma_enabled(stm32_port))
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+
+	if (stm32_usart_tx_dma_started(stm32_port))
+		stm32_usart_tx_dma_terminate(stm32_port);
+
 	/* Disable modem control interrupts */
 	stm32_usart_disable_ms(port);
 
@@ -1419,8 +1458,6 @@ static int stm32_usart_of_dma_tx_probe(struct stm32_port *stm32port,
 	struct dma_slave_config config;
 	int ret;
 
-	stm32port->tx_dma_busy = false;
-
 	stm32port->tx_buf = dma_alloc_coherent(dev, TX_BUF_L,
 					       &stm32port->tx_dma_buf,
 					       GFP_KERNEL);
@@ -1570,7 +1607,6 @@ static int stm32_usart_serial_remove(struct platform_device *pdev)
 	writel_relaxed(cr3, port->membase + ofs->cr3);
 
 	if (stm32_port->tx_ch) {
-		dmaengine_terminate_async(stm32_port->tx_ch);
 		stm32_usart_of_dma_tx_remove(stm32_port, pdev);
 		dma_release_channel(stm32_port->tx_ch);
 	}
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index e23916bfbb60..feab952aec16 100644
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -264,7 +264,7 @@ struct stm32_port {
 	u32 cr1_irq;		 /* USART_CR1_RXNEIE or RTOIE */
 	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
 	int last_res;
-	bool tx_dma_busy;	 /* dma tx busy               */
+	bool tx_dma_busy;	 /* dma tx transaction in progress */
 	bool throttled;		 /* port throttled            */
 	bool hw_flow_control;
 	bool swap;		 /* swap RX & TX pins */
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 425a016f9db7..98b2f4fb9a99 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -127,7 +127,8 @@ static void serial_out(struct uart_sunsu_port *up, int offset, int value)
 	 * gate outputs a logical one. Since we use level triggered interrupts
 	 * we have lockup and watchdog reset. We cannot mask IRQ because
 	 * keyboard shares IRQ with us (Word has it as Bob Smelik's design).
-	 * This problem is similar to what Alpha people suffer, see serial.c.
+	 * This problem is similar to what Alpha people suffer, see
+	 * 8250_alpha.c.
 	 */
 	if (offset == UART_MCR)
 		value |= UART_MCR_OUT2;
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index d3d9566e5dbd..e1fa52d31474 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -626,7 +626,7 @@ static struct uart_driver ulite_uart_driver = {
  *
  * Returns: 0 on success, <0 otherwise
  */
-static int ulite_assign(struct device *dev, int id, u32 base, int irq,
+static int ulite_assign(struct device *dev, int id, phys_addr_t base, int irq,
 			struct uartlite_data *pdata)
 {
 	struct uart_port *port;
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index e15b2bf69904..9adfe3dc970f 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -621,21 +621,25 @@ static const struct of_device_id wmt_dt_ids[] = {
 static int vt8500_serial_probe(struct platform_device *pdev)
 {
 	struct vt8500_port *vt8500_port;
-	struct resource *mmres, *irqres;
+	struct resource *mmres;
 	struct device_node *np = pdev->dev.of_node;
 	const unsigned int *flags;
 	int ret;
 	int port;
+	int irq;
 
 	flags = of_device_get_match_data(&pdev->dev);
 	if (!flags)
 		return -EINVAL;
 
 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!mmres || !irqres)
+	if (!mmres)
 		return -ENODEV;
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
 	if (np) {
 		port = of_alias_get_id(np, "serial");
 		if (port >= VT8500_MAX_PORTS)
@@ -688,7 +692,7 @@ static int vt8500_serial_probe(struct platform_device *pdev)
 	vt8500_port->uart.type = PORT_VT8500;
 	vt8500_port->uart.iotype = UPIO_MEM;
 	vt8500_port->uart.mapbase = mmres->start;
-	vt8500_port->uart.irq = irqres->start;
+	vt8500_port->uart.irq = irq;
 	vt8500_port->uart.fifosize = 16;
 	vt8500_port->uart.ops = &vt8500_uart_pops;
 	vt8500_port->uart.line = port;
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 6c7e65b1d9a1..646510476c30 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -39,20 +39,15 @@
 #define TTY_BUFFER_PAGE	(((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
 
 /**
- *	tty_buffer_lock_exclusive	-	gain exclusive access to buffer
- *	tty_buffer_unlock_exclusive	-	release exclusive access
+ * tty_buffer_lock_exclusive	-	gain exclusive access to buffer
+ * @port: tty port owning the flip buffer
  *
- *	@port: tty port owning the flip buffer
+ * Guarantees safe use of the &tty_ldisc_ops.receive_buf() method by excluding
+ * the buffer work and any pending flush from using the flip buffer. Data can
+ * continue to be added concurrently to the flip buffer from the driver side.
  *
- *	Guarantees safe use of the line discipline's receive_buf() method by
- *	excluding the buffer work and any pending flush from using the flip
- *	buffer. Data can continue to be added concurrently to the flip buffer
- *	from the driver side.
- *
- *	On release, the buffer work is restarted if there is data in the
- *	flip buffer
+ * See also tty_buffer_unlock_exclusive().
  */
-
 void tty_buffer_lock_exclusive(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
@@ -62,6 +57,14 @@ void tty_buffer_lock_exclusive(struct tty_port *port)
 }
 EXPORT_SYMBOL_GPL(tty_buffer_lock_exclusive);
 
+/**
+ * tty_buffer_unlock_exclusive	-	release exclusive access
+ * @port: tty port owning the flip buffer
+ *
+ * The buffer work is restarted if there is data in the flip buffer.
+ *
+ * See also tty_buffer_lock_exclusive().
+ */
 void tty_buffer_unlock_exclusive(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
@@ -77,17 +80,16 @@ void tty_buffer_unlock_exclusive(struct tty_port *port)
 EXPORT_SYMBOL_GPL(tty_buffer_unlock_exclusive);
 
 /**
- *	tty_buffer_space_avail	-	return unused buffer space
- *	@port: tty port owning the flip buffer
+ * tty_buffer_space_avail	-	return unused buffer space
+ * @port: tty port owning the flip buffer
  *
- *	Returns the # of bytes which can be written by the driver without
- *	reaching the buffer limit.
+ * Returns: the # of bytes which can be written by the driver without reaching
+ * the buffer limit.
  *
- *	Note: this does not guarantee that memory is available to write
- *	the returned # of bytes (use tty_prepare_flip_string_xxx() to
- *	pre-allocate if memory guarantee is required).
+ * Note: this does not guarantee that memory is available to write the returned
+ * # of bytes (use tty_prepare_flip_string() to pre-allocate if memory
+ * guarantee is required).
  */
-
 unsigned int tty_buffer_space_avail(struct tty_port *port)
 {
 	int space = port->buf.mem_limit - atomic_read(&port->buf.mem_used);
@@ -107,13 +109,12 @@ static void tty_buffer_reset(struct tty_buffer *p, size_t size)
 }
 
 /**
- *	tty_buffer_free_all		-	free buffers used by a tty
- *	@port: tty port to free from
+ * tty_buffer_free_all		-	free buffers used by a tty
+ * @port: tty port to free from
  *
- *	Remove all the buffers pending on a tty whether queued with data
- *	or in the free ring. Must be called when the tty is no longer in use
+ * Remove all the buffers pending on a tty whether queued with data or in the
+ * free ring. Must be called when the tty is no longer in use.
  */
-
 void tty_buffer_free_all(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
@@ -142,17 +143,17 @@ void tty_buffer_free_all(struct tty_port *port)
 }
 
 /**
- *	tty_buffer_alloc	-	allocate a tty buffer
- *	@port: tty port
- *	@size: desired size (characters)
- *
- *	Allocate a new tty buffer to hold the desired number of characters.
- *	We round our buffers off in 256 character chunks to get better
- *	allocation behaviour.
- *	Return NULL if out of memory or the allocation would exceed the
- *	per device queue
+ * tty_buffer_alloc	-	allocate a tty buffer
+ * @port: tty port
+ * @size: desired size (characters)
+ *
+ * Allocate a new tty buffer to hold the desired number of characters. We
+ * round our buffers off in 256 character chunks to get better allocation
+ * behaviour.
+ *
+ * Returns: %NULL if out of memory or the allocation would exceed the per
+ * device queue.
  */
-
 static struct tty_buffer *tty_buffer_alloc(struct tty_port *port, size_t size)
 {
 	struct llist_node *free;
@@ -185,14 +186,13 @@ found:
 }
 
 /**
- *	tty_buffer_free		-	free a tty buffer
- *	@port: tty port owning the buffer
- *	@b: the buffer to free
+ * tty_buffer_free		-	free a tty buffer
+ * @port: tty port owning the buffer
+ * @b: the buffer to free
  *
- *	Free a tty buffer, or add it to the free list according to our
- *	internal strategy
+ * Free a tty buffer, or add it to the free list according to our internal
+ * strategy.
  */
-
 static void tty_buffer_free(struct tty_port *port, struct tty_buffer *b)
 {
 	struct tty_bufhead *buf = &port->buf;
@@ -207,17 +207,15 @@ static void tty_buffer_free(struct tty_port *port, struct tty_buffer *b)
 }
 
 /**
- *	tty_buffer_flush		-	flush full tty buffers
- *	@tty: tty to flush
- *	@ld:  optional ldisc ptr (must be referenced)
+ * tty_buffer_flush		-	flush full tty buffers
+ * @tty: tty to flush
+ * @ld: optional ldisc ptr (must be referenced)
  *
- *	flush all the buffers containing receive data. If ld != NULL,
- *	flush the ldisc input buffer.
+ * Flush all the buffers containing receive data. If @ld != %NULL, flush the
+ * ldisc input buffer.
  *
- *	Locking: takes buffer lock to ensure single-threaded flip buffer
- *		 'consumer'
+ * Locking: takes buffer lock to ensure single-threaded flip buffer 'consumer'.
  */
-
 void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
 {
 	struct tty_port *port = tty->port;
@@ -244,17 +242,18 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
 }
 
 /**
- *	__tty_buffer_request_room		-	grow tty buffer if needed
- *	@port: tty port
- *	@size: size desired
- *	@flags: buffer flags if new buffer allocated (default = 0)
+ * __tty_buffer_request_room	-	grow tty buffer if needed
+ * @port: tty port
+ * @size: size desired
+ * @flags: buffer flags if new buffer allocated (default = 0)
+ *
+ * Make at least @size bytes of linear space available for the tty buffer.
  *
- *	Make at least size bytes of linear space available for the tty
- *	buffer. If we fail return the size we managed to find.
+ * Will change over to a new buffer if the current buffer is encoded as
+ * %TTY_NORMAL (so has no flags buffer) and the new buffer requires a flags
+ * buffer.
  *
- *	Will change over to a new buffer if the current buffer is encoded as
- *	TTY_NORMAL (so has no flags buffer) and the new buffer requires
- *	a flags buffer.
+ * Returns: the size we managed to find.
  */
 static int __tty_buffer_request_room(struct tty_port *port, size_t size,
 				     int flags)
@@ -300,16 +299,17 @@ int tty_buffer_request_room(struct tty_port *port, size_t size)
 EXPORT_SYMBOL_GPL(tty_buffer_request_room);
 
 /**
- *	tty_insert_flip_string_fixed_flag - Add characters to the tty buffer
- *	@port: tty port
- *	@chars: characters
- *	@flag: flag value for each character
- *	@size: size
- *
- *	Queue a series of bytes to the tty buffering. All the characters
- *	passed are marked with the supplied flag. Returns the number added.
+ * tty_insert_flip_string_fixed_flag - add characters to the tty buffer
+ * @port: tty port
+ * @chars: characters
+ * @flag: flag value for each character
+ * @size: size
+ *
+ * Queue a series of bytes to the tty buffering. All the characters passed are
+ * marked with the supplied flag.
+ *
+ * Returns: the number added.
  */
-
 int tty_insert_flip_string_fixed_flag(struct tty_port *port,
 		const unsigned char *chars, char flag, size_t size)
 {
@@ -338,17 +338,17 @@ int tty_insert_flip_string_fixed_flag(struct tty_port *port,
 EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag);
 
 /**
- *	tty_insert_flip_string_flags	-	Add characters to the tty buffer
- *	@port: tty port
- *	@chars: characters
- *	@flags: flag bytes
- *	@size: size
- *
- *	Queue a series of bytes to the tty buffering. For each character
- *	the flags array indicates the status of the character. Returns the
- *	number added.
+ * tty_insert_flip_string_flags	-	add characters to the tty buffer
+ * @port: tty port
+ * @chars: characters
+ * @flags: flag bytes
+ * @size: size
+ *
+ * Queue a series of bytes to the tty buffering. For each character the flags
+ * array indicates the status of the character.
+ *
+ * Returns: the number added.
  */
-
 int tty_insert_flip_string_flags(struct tty_port *port,
 		const unsigned char *chars, const char *flags, size_t size)
 {
@@ -376,13 +376,13 @@ int tty_insert_flip_string_flags(struct tty_port *port,
 EXPORT_SYMBOL(tty_insert_flip_string_flags);
 
 /**
- *	__tty_insert_flip_char   -	Add one character to the tty buffer
- *	@port: tty port
- *	@ch: character
- *	@flag: flag byte
+ * __tty_insert_flip_char   -	add one character to the tty buffer
+ * @port: tty port
+ * @ch: character
+ * @flag: flag byte
  *
- *	Queue a single byte to the tty buffering, with an optional flag.
- *	This is the slow path of tty_insert_flip_char.
+ * Queue a single byte @ch to the tty buffering, with an optional flag. This is
+ * the slow path of tty_insert_flip_char().
  */
 int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag)
 {
@@ -402,39 +402,19 @@ int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag)
 EXPORT_SYMBOL(__tty_insert_flip_char);
 
 /**
- *	tty_schedule_flip	-	push characters to ldisc
- *	@port: tty port to push from
+ * tty_prepare_flip_string	-	make room for characters
+ * @port: tty port
+ * @chars: return pointer for character write area
+ * @size: desired size
  *
- *	Takes any pending buffers and transfers their ownership to the
- *	ldisc side of the queue. It then schedules those characters for
- *	processing by the line discipline.
- */
-
-void tty_schedule_flip(struct tty_port *port)
-{
-	struct tty_bufhead *buf = &port->buf;
-
-	/* paired w/ acquire in flush_to_ldisc(); ensures
-	 * flush_to_ldisc() sees buffer data.
-	 */
-	smp_store_release(&buf->tail->commit, buf->tail->used);
-	queue_work(system_unbound_wq, &buf->work);
-}
-EXPORT_SYMBOL(tty_schedule_flip);
-
-/**
- *	tty_prepare_flip_string		-	make room for characters
- *	@port: tty port
- *	@chars: return pointer for character write area
- *	@size: desired size
- *
- *	Prepare a block of space in the buffer for data. Returns the length
- *	available and buffer pointer to the space which is now allocated and
- *	accounted for as ready for normal characters. This is used for drivers
- *	that need their own block copy routines into the buffer. There is no
- *	guarantee the buffer is a DMA target!
+ * Prepare a block of space in the buffer for data.
+ *
+ * This is used for drivers that need their own block copy routines into the
+ * buffer. There is no guarantee the buffer is a DMA target!
+ *
+ * Returns: the length available and buffer pointer (@chars) to the space which
+ * is now allocated and accounted for as ready for normal characters.
  */
-
 int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars,
 		size_t size)
 {
@@ -453,16 +433,16 @@ int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars,
 EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
 
 /**
- *	tty_ldisc_receive_buf		-	forward data to line discipline
- *	@ld:	line discipline to process input
- *	@p:	char buffer
- *	@f:	TTY_* flags buffer
- *	@count:	number of bytes to process
+ * tty_ldisc_receive_buf	-	forward data to line discipline
+ * @ld: line discipline to process input
+ * @p: char buffer
+ * @f: %TTY_NORMAL, %TTY_BREAK, etc. flags buffer
+ * @count: number of bytes to process
  *
- *	Callers other than flush_to_ldisc() need to exclude the kworker
- *	from concurrent use of the line discipline, see paste_selection().
+ * Callers other than flush_to_ldisc() need to exclude the kworker from
+ * concurrent use of the line discipline, see paste_selection().
  *
- *	Returns the number of bytes processed
+ * Returns: the number of bytes processed.
  */
 int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
 			  const char *f, int count)
@@ -495,18 +475,16 @@ receive_buf(struct tty_port *port, struct tty_buffer *head, int count)
 }
 
 /**
- *	flush_to_ldisc
- *	@work: tty structure passed from work queue.
+ * flush_to_ldisc		-	flush data from buffer to ldisc
+ * @work: tty structure passed from work queue.
  *
- *	This routine is called out of the software interrupt to flush data
- *	from the buffer chain to the line discipline.
+ * This routine is called out of the software interrupt to flush data from the
+ * buffer chain to the line discipline.
  *
- *	The receive_buf method is single threaded for each tty instance.
+ * The receive_buf() method is single threaded for each tty instance.
  *
- *	Locking: takes buffer lock to ensure single-threaded flip buffer
- *		 'consumer'
+ * Locking: takes buffer lock to ensure single-threaded flip buffer 'consumer'.
  */
-
 static void flush_to_ldisc(struct work_struct *work)
 {
 	struct tty_port *port = container_of(work, struct tty_port, buf.work);
@@ -554,30 +532,35 @@ static void flush_to_ldisc(struct work_struct *work)
 }
 
 /**
- *	tty_flip_buffer_push	-	terminal
- *	@port: tty port to push
+ * tty_flip_buffer_push		-	push terminal buffers
+ * @port: tty port to push
  *
- *	Queue a push of the terminal flip buffers to the line discipline.
- *	Can be called from IRQ/atomic context.
+ * Queue a push of the terminal flip buffers to the line discipline. Can be
+ * called from IRQ/atomic context.
  *
- *	In the event of the queue being busy for flipping the work will be
- *	held off and retried later.
+ * In the event of the queue being busy for flipping the work will be held off
+ * and retried later.
  */
-
 void tty_flip_buffer_push(struct tty_port *port)
 {
-	tty_schedule_flip(port);
+	struct tty_bufhead *buf = &port->buf;
+
+	/*
+	 * Paired w/ acquire in flush_to_ldisc(); ensures flush_to_ldisc() sees
+	 * buffer data.
+	 */
+	smp_store_release(&buf->tail->commit, buf->tail->used);
+	queue_work(system_unbound_wq, &buf->work);
 }
 EXPORT_SYMBOL(tty_flip_buffer_push);
 
 /**
- *	tty_buffer_init		-	prepare a tty buffer structure
- *	@port: tty port to initialise
+ * tty_buffer_init		-	prepare a tty buffer structure
+ * @port: tty port to initialise
  *
- *	Set up the initial state of the buffer management for a tty device.
- *	Must be called before the other tty buffer functions are used.
+ * Set up the initial state of the buffer management for a tty device. Must be
+ * called before the other tty buffer functions are used.
  */
-
 void tty_buffer_init(struct tty_port *port)
 {
 	struct tty_bufhead *buf = &port->buf;
@@ -594,14 +577,14 @@ void tty_buffer_init(struct tty_port *port)
 }
 
 /**
- *	tty_buffer_set_limit	-	change the tty buffer memory limit
- *	@port: tty port to change
- *	@limit: memory limit to set
+ * tty_buffer_set_limit		-	change the tty buffer memory limit
+ * @port: tty port to change
+ * @limit: memory limit to set
  *
- *	Change the tty buffer memory limit.
- *	Must be called before the other tty buffer functions are used.
+ * Change the tty buffer memory limit.
+ *
+ * Must be called before the other tty buffer functions are used.
  */
-
 int tty_buffer_set_limit(struct tty_port *port, int limit)
 {
 	if (limit < MIN_TTYB_SIZE)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 6616d4a0d41d..7e8b3bd59c7b 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -158,19 +158,18 @@ static int tty_fasync(int fd, struct file *filp, int on);
 static void release_tty(struct tty_struct *tty, int idx);
 
 /**
- *	free_tty_struct		-	free a disused tty
- *	@tty: tty struct to free
+ * free_tty_struct	-	free a disused tty
+ * @tty: tty struct to free
  *
- *	Free the write buffers, tty queue and tty memory itself.
+ * Free the write buffers, tty queue and tty memory itself.
  *
- *	Locking: none. Must be called after tty is definitely unused
+ * Locking: none. Must be called after tty is definitely unused
  */
-
 static void free_tty_struct(struct tty_struct *tty)
 {
 	tty_ldisc_deinit(tty);
 	put_device(tty->dev);
-	kfree(tty->write_buf);
+	kvfree(tty->write_buf);
 	tty->magic = 0xDEADDEAD;
 	kfree(tty);
 }
@@ -206,8 +205,9 @@ void tty_add_file(struct tty_struct *tty, struct file *file)
 	spin_unlock(&tty->files_lock);
 }
 
-/*
+/**
  * tty_free_file - free file->private_data
+ * @file: to free private_data of
  *
  * This shall be used only for fail path handling when tty_add_file was not
  * called yet.
@@ -233,15 +233,14 @@ static void tty_del_file(struct file *file)
 }
 
 /**
- *	tty_name	-	return tty naming
- *	@tty: tty structure
+ * tty_name	-	return tty naming
+ * @tty: tty structure
  *
- *	Convert a tty structure into a name. The name reflects the kernel
- *	naming policy and if udev is in use may not reflect user space
+ * Convert a tty structure into a name. The name reflects the kernel naming
+ * policy and if udev is in use may not reflect user space
  *
- *	Locking: none
+ * Locking: none
  */
-
 const char *tty_name(const struct tty_struct *tty)
 {
 	if (!tty) /* Hmm.  NULL pointer.  That's fun. */
@@ -303,16 +302,15 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 }
 
 /**
- *	get_tty_driver		-	find device of a tty
- *	@device: device identifier
- *	@index: returns the index of the tty
+ * get_tty_driver		-	find device of a tty
+ * @device: device identifier
+ * @index: returns the index of the tty
  *
- *	This routine returns a tty driver structure, given a device number
- *	and also passes back the index number.
+ * This routine returns a tty driver structure, given a device number and also
+ * passes back the index number.
  *
- *	Locking: caller must hold tty_mutex
+ * Locking: caller must hold tty_mutex
  */
-
 static struct tty_driver *get_tty_driver(dev_t device, int *index)
 {
 	struct tty_driver *p;
@@ -329,17 +327,17 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
 }
 
 /**
- *	tty_dev_name_to_number	-	return dev_t for device name
- *	@name: user space name of device under /dev
- *	@number: pointer to dev_t that this function will populate
+ * tty_dev_name_to_number	-	return dev_t for device name
+ * @name: user space name of device under /dev
+ * @number: pointer to dev_t that this function will populate
  *
- *	This function converts device names like ttyS0 or ttyUSB1 into dev_t
- *	like (4, 64) or (188, 1). If no corresponding driver is registered then
- *	the function returns -ENODEV.
+ * This function converts device names like ttyS0 or ttyUSB1 into dev_t like
+ * (4, 64) or (188, 1). If no corresponding driver is registered then the
+ * function returns -%ENODEV.
  *
- *	Locking: this acquires tty_mutex to protect the tty_drivers list from
- *		being modified while we are traversing it, and makes sure to
- *		release it before exiting.
+ * Locking: this acquires tty_mutex to protect the tty_drivers list from
+ *	being modified while we are traversing it, and makes sure to
+ *	release it before exiting.
  */
 int tty_dev_name_to_number(const char *name, dev_t *number)
 {
@@ -381,13 +379,12 @@ EXPORT_SYMBOL_GPL(tty_dev_name_to_number);
 #ifdef CONFIG_CONSOLE_POLL
 
 /**
- *	tty_find_polling_driver	-	find device of a polled tty
- *	@name: name string to match
- *	@line: pointer to resulting tty line nr
+ * tty_find_polling_driver	-	find device of a polled tty
+ * @name: name string to match
+ * @line: pointer to resulting tty line nr
  *
- *	This routine returns a tty driver structure, given a name
- *	and the condition that the tty driver is capable of polled
- *	operation.
+ * This routine returns a tty driver structure, given a name and the condition
+ * that the tty driver is capable of polled operation.
  */
 struct tty_driver *tty_find_polling_driver(char *name, int *line)
 {
@@ -515,14 +512,13 @@ static DEFINE_SPINLOCK(redirect_lock);
 static struct file *redirect;
 
 /**
- *	tty_wakeup	-	request more data
- *	@tty: terminal
+ * tty_wakeup	-	request more data
+ * @tty: terminal
  *
- *	Internal and external helper for wakeups of tty. This function
- *	informs the line discipline if present that the driver is ready
- *	to receive more output data.
+ * Internal and external helper for wakeups of tty. This function informs the
+ * line discipline if present that the driver is ready to receive more output
+ * data.
  */
-
 void tty_wakeup(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld;
@@ -540,11 +536,11 @@ void tty_wakeup(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_wakeup);
 
 /**
- *	tty_release_redirect	-	Release a redirect on a pty if present
- *	@tty: tty device
+ * tty_release_redirect	-	Release a redirect on a pty if present
+ * @tty: tty device
  *
- *	This is available to the pty code so if the master closes, if the
- *	slave is a redirect it can release the redirect.
+ * This is available to the pty code so if the master closes, if the slave is a
+ * redirect it can release the redirect.
  */
 static struct file *tty_release_redirect(struct tty_struct *tty)
 {
@@ -561,27 +557,29 @@ static struct file *tty_release_redirect(struct tty_struct *tty)
 }
 
 /**
- *	__tty_hangup		-	actual handler for hangup events
- *	@tty: tty device
- *	@exit_session: if non-zero, signal all foreground group processes
+ * __tty_hangup		-	actual handler for hangup events
+ * @tty: tty device
+ * @exit_session: if non-zero, signal all foreground group processes
+ *
+ * This can be called by a "kworker" kernel thread. That is process synchronous
+ * but doesn't hold any locks, so we need to make sure we have the appropriate
+ * locks for what we're doing.
+ *
+ * The hangup event clears any pending redirections onto the hung up device. It
+ * ensures future writes will error and it does the needed line discipline
+ * hangup and signal delivery. The tty object itself remains intact.
+ *
+ * Locking:
+ *  * BTM
  *
- *	This can be called by a "kworker" kernel thread.  That is process
- *	synchronous but doesn't hold any locks, so we need to make sure we
- *	have the appropriate locks for what we're doing.
+ *   * redirect lock for undoing redirection
+ *   * file list lock for manipulating list of ttys
+ *   * tty_ldiscs_lock from called functions
+ *   * termios_rwsem resetting termios data
+ *   * tasklist_lock to walk task list for hangup event
  *
- *	The hangup event clears any pending redirections onto the hung up
- *	device. It ensures future writes will error and it does the needed
- *	line discipline hangup and signal delivery. The tty object itself
- *	remains intact.
+ *    * ->siglock to protect ->signal/->sighand
  *
- *	Locking:
- *		BTM
- *		  redirect lock for undoing redirection
- *		  file list lock for manipulating list of ttys
- *		  tty_ldiscs_lock from called functions
- *		  termios_rwsem resetting termios data
- *		  tasklist_lock to walk task list for hangup event
- *		    ->siglock to protect ->signal/->sighand
  */
 static void __tty_hangup(struct tty_struct *tty, int exit_session)
 {
@@ -682,13 +680,12 @@ static void do_tty_hangup(struct work_struct *work)
 }
 
 /**
- *	tty_hangup		-	trigger a hangup event
- *	@tty: tty to hangup
+ * tty_hangup		-	trigger a hangup event
+ * @tty: tty to hangup
  *
- *	A carrier loss (virtual or otherwise) has occurred on this like
- *	schedule a hangup sequence to run after this event.
+ * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a
+ * hangup sequence to run after this event.
  */
-
 void tty_hangup(struct tty_struct *tty)
 {
 	tty_debug_hangup(tty, "hangup\n");
@@ -697,14 +694,13 @@ void tty_hangup(struct tty_struct *tty)
 EXPORT_SYMBOL(tty_hangup);
 
 /**
- *	tty_vhangup		-	process vhangup
- *	@tty: tty to hangup
+ * tty_vhangup		-	process vhangup
+ * @tty: tty to hangup
  *
- *	The user has asked via system call for the terminal to be hung up.
- *	We do this synchronously so that when the syscall returns the process
- *	is complete. That guarantee is necessary for security reasons.
+ * The user has asked via system call for the terminal to be hung up. We do
+ * this synchronously so that when the syscall returns the process is complete.
+ * That guarantee is necessary for security reasons.
  */
-
 void tty_vhangup(struct tty_struct *tty)
 {
 	tty_debug_hangup(tty, "vhangup\n");
@@ -714,11 +710,10 @@ EXPORT_SYMBOL(tty_vhangup);
 
 
 /**
- *	tty_vhangup_self	-	process vhangup for own ctty
+ * tty_vhangup_self	-	process vhangup for own ctty
  *
- *	Perform a vhangup on the current controlling tty
+ * Perform a vhangup on the current controlling tty
  */
-
 void tty_vhangup_self(void)
 {
 	struct tty_struct *tty;
@@ -731,16 +726,15 @@ void tty_vhangup_self(void)
 }
 
 /**
- *	tty_vhangup_session		-	hangup session leader exit
- *	@tty: tty to hangup
+ * tty_vhangup_session	-	hangup session leader exit
+ * @tty: tty to hangup
  *
- *	The session leader is exiting and hanging up its controlling terminal.
- *	Every process in the foreground process group is signalled SIGHUP.
+ * The session leader is exiting and hanging up its controlling terminal.
+ * Every process in the foreground process group is signalled %SIGHUP.
  *
- *	We do this synchronously so that when the syscall returns the process
- *	is complete. That guarantee is necessary for security reasons.
+ * We do this synchronously so that when the syscall returns the process is
+ * complete. That guarantee is necessary for security reasons.
  */
-
 void tty_vhangup_session(struct tty_struct *tty)
 {
 	tty_debug_hangup(tty, "session hangup\n");
@@ -748,13 +742,11 @@ void tty_vhangup_session(struct tty_struct *tty)
 }
 
 /**
- *	tty_hung_up_p		-	was tty hung up
- *	@filp: file pointer of tty
+ * tty_hung_up_p	-	was tty hung up
+ * @filp: file pointer of tty
  *
- *	Return true if the tty has been subject to a vhangup or a carrier
- *	loss
+ * Return: true if the tty has been subject to a vhangup or a carrier loss
  */
-
 int tty_hung_up_p(struct file *filp)
 {
 	return (filp && filp->f_op == &hung_up_tty_fops);
@@ -771,20 +763,18 @@ void __stop_tty(struct tty_struct *tty)
 }
 
 /**
- *	stop_tty	-	propagate flow control
- *	@tty: tty to stop
+ * stop_tty	-	propagate flow control
+ * @tty: tty to stop
  *
- *	Perform flow control to the driver. May be called
- *	on an already stopped device and will not re-call the driver
- *	method.
+ * Perform flow control to the driver. May be called on an already stopped
+ * device and will not re-call the &tty_driver->stop() method.
  *
- *	This functionality is used by both the line disciplines for
- *	halting incoming flow and by the driver. It may therefore be
- *	called from any context, may be under the tty atomic_write_lock
- *	but not always.
+ * This functionality is used by both the line disciplines for halting incoming
+ * flow and by the driver. It may therefore be called from any context, may be
+ * under the tty %atomic_write_lock but not always.
  *
- *	Locking:
- *		flow.lock
+ * Locking:
+ *	flow.lock
  */
 void stop_tty(struct tty_struct *tty)
 {
@@ -807,15 +797,15 @@ void __start_tty(struct tty_struct *tty)
 }
 
 /**
- *	start_tty	-	propagate flow control
- *	@tty: tty to start
+ * start_tty	-	propagate flow control
+ * @tty: tty to start
  *
- *	Start a tty that has been stopped if at all possible. If this
- *	tty was previous stopped and is now being started, the driver
- *	start method is invoked and the line discipline woken.
+ * Start a tty that has been stopped if at all possible. If @tty was previously
+ * stopped and is now being started, the &tty_driver->start() method is invoked
+ * and the line discipline woken.
  *
- *	Locking:
- *		flow.lock
+ * Locking:
+ *	flow.lock
  */
 void start_tty(struct tty_struct *tty)
 {
@@ -908,18 +898,17 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
 
 
 /**
- *	tty_read	-	read method for tty device files
- *	@iocb: kernel I/O control block
- *	@to: destination for the data read
+ * tty_read	-	read method for tty device files
+ * @iocb: kernel I/O control block
+ * @to: destination for the data read
  *
- *	Perform the read system call function on this terminal device. Checks
- *	for hung up devices before calling the line discipline method.
+ * Perform the read system call function on this terminal device. Checks
+ * for hung up devices before calling the line discipline method.
  *
- *	Locking:
- *		Locks the line discipline internally while needed. Multiple
- *	read calls may be outstanding in parallel.
+ * Locking:
+ *	Locks the line discipline internally while needed. Multiple read calls
+ *	may be outstanding in parallel.
  */
-
 static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
 {
 	int i;
@@ -997,9 +986,6 @@ static inline ssize_t do_tty_write(
 	 * layer has problems with bigger chunks. It will
 	 * claim to be able to handle more characters than
 	 * it actually does.
-	 *
-	 * FIXME: This can probably go away now except that 64K chunks
-	 * are too likely to fail unless switched to vmalloc...
 	 */
 	chunk = 2048;
 	if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
@@ -1014,12 +1000,12 @@ static inline ssize_t do_tty_write(
 		if (chunk < 1024)
 			chunk = 1024;
 
-		buf_chunk = kmalloc(chunk, GFP_KERNEL);
+		buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 		if (!buf_chunk) {
 			ret = -ENOMEM;
 			goto out;
 		}
-		kfree(tty->write_buf);
+		kvfree(tty->write_buf);
 		tty->write_cnt = chunk;
 		tty->write_buf = buf_chunk;
 	}
@@ -1069,13 +1055,12 @@ out:
  * @tty: the destination tty_struct
  * @msg: the message to write
  *
- * This is used for messages that need to be redirected to a specific tty.
- * We don't put it into the syslog queue right now maybe in the future if
- * really needed.
+ * This is used for messages that need to be redirected to a specific tty. We
+ * don't put it into the syslog queue right now maybe in the future if really
+ * needed.
  *
  * We must still hold the BTM and test the CLOSING flag for the moment.
  */
-
 void tty_write_message(struct tty_struct *tty, char *msg)
 {
 	if (tty) {
@@ -1113,18 +1098,18 @@ static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_
 }
 
 /**
- *	tty_write		-	write method for tty device file
- *	@iocb: kernel I/O control block
- *	@from: iov_iter with data to write
+ * tty_write		-	write method for tty device file
+ * @iocb: kernel I/O control block
+ * @from: iov_iter with data to write
  *
- *	Write data to a tty device via the line discipline.
+ * Write data to a tty device via the line discipline.
  *
- *	Locking:
- *		Locks the line discipline as required
- *		Writes to the tty driver are serialized by the atomic_write_lock
- *		and are then processed in chunks to the device. The line
- *		discipline write method will not be invoked in parallel for
- *		each device.
+ * Locking:
+ *	Locks the line discipline as required
+ *	Writes to the tty driver are serialized by the atomic_write_lock
+ *	and are then processed in chunks to the device. The line
+ *	discipline write method will not be invoked in parallel for
+ *	each device.
  */
 static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from)
 {
@@ -1154,14 +1139,15 @@ ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter)
 	return tty_write(iocb, iter);
 }
 
-/*
- *	tty_send_xchar	-	send priority character
+/**
+ * tty_send_xchar	-	send priority character
+ * @tty: the tty to send to
+ * @ch: xchar to send
  *
- *	Send a high priority character to the tty even if stopped
+ * Send a high priority character to the tty even if stopped.
  *
- *	Locking: none for xchar method, write ordering for write method.
+ * Locking: none for xchar method, write ordering for write method.
  */
-
 int tty_send_xchar(struct tty_struct *tty, char ch)
 {
 	bool was_stopped = tty->flow.stopped;
@@ -1188,15 +1174,15 @@ int tty_send_xchar(struct tty_struct *tty, char ch)
 }
 
 /**
- *	pty_line_name	-	generate name for a pty
- *	@driver: the tty driver in use
- *	@index: the minor number
- *	@p: output buffer of at least 6 bytes
+ * pty_line_name	-	generate name for a pty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 6 bytes
  *
- *	Generate a name from a driver reference and write it to the output
- *	buffer.
+ * Generate a name from a @driver reference and write it to the output buffer
+ * @p.
  *
- *	Locking: None
+ * Locking: None
  */
 static void pty_line_name(struct tty_driver *driver, int index, char *p)
 {
@@ -1209,15 +1195,15 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
 }
 
 /**
- *	tty_line_name	-	generate name for a tty
- *	@driver: the tty driver in use
- *	@index: the minor number
- *	@p: output buffer of at least 7 bytes
+ * tty_line_name	-	generate name for a tty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 7 bytes
  *
- *	Generate a name from a driver reference and write it to the output
- *	buffer.
+ * Generate a name from a @driver reference and write it to the output buffer
+ * @p.
  *
- *	Locking: None
+ * Locking: None
  */
 static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
 {
@@ -1229,15 +1215,15 @@ static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
 }
 
 /**
- *	tty_driver_lookup_tty() - find an existing tty, if any
- *	@driver: the driver for the tty
- *	@file:   file object
- *	@idx:	 the minor number
+ * tty_driver_lookup_tty() - find an existing tty, if any
+ * @driver: the driver for the tty
+ * @file: file object
+ * @idx: the minor number
  *
- *	Return the tty, if found. If not found, return NULL or ERR_PTR() if the
- *	driver lookup() method returns an error.
+ * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the
+ * driver lookup() method returns an error.
  *
- *	Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
+ * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
  */
 static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
 		struct file *file, int idx)
@@ -1258,13 +1244,12 @@ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
 }
 
 /**
- *	tty_init_termios	-  helper for termios setup
- *	@tty: the tty to set up
+ * tty_init_termios	-  helper for termios setup
+ * @tty: the tty to set up
  *
- *	Initialise the termios structure for this tty. This runs under
- *	the tty_mutex currently so we can be relaxed about ordering.
+ * Initialise the termios structure for this tty. This runs under the
+ * %tty_mutex currently so we can be relaxed about ordering.
  */
-
 void tty_init_termios(struct tty_struct *tty)
 {
 	struct ktermios *tp;
@@ -1287,6 +1272,14 @@ void tty_init_termios(struct tty_struct *tty)
 }
 EXPORT_SYMBOL_GPL(tty_init_termios);
 
+/**
+ * tty_standard_install - usual tty->ops->install
+ * @driver: the driver for the tty
+ * @tty: the tty
+ *
+ * If the @driver overrides @tty->ops->install, it still can call this function
+ * to perform the standard install operations.
+ */
 int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	tty_init_termios(tty);
@@ -1298,16 +1291,15 @@ int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_standard_install);
 
 /**
- *	tty_driver_install_tty() - install a tty entry in the driver
- *	@driver: the driver for the tty
- *	@tty: the tty
+ * tty_driver_install_tty() - install a tty entry in the driver
+ * @driver: the driver for the tty
+ * @tty: the tty
  *
- *	Install a tty object into the driver tables. The tty->index field
- *	will be set by the time this is called. This method is responsible
- *	for ensuring any need additional structures are allocated and
- *	configured.
+ * Install a tty object into the driver tables. The @tty->index field will be
+ * set by the time this is called. This method is responsible for ensuring any
+ * need additional structures are allocated and configured.
  *
- *	Locking: tty_mutex for now
+ * Locking: tty_mutex for now
  */
 static int tty_driver_install_tty(struct tty_driver *driver,
 						struct tty_struct *tty)
@@ -1317,14 +1309,14 @@ static int tty_driver_install_tty(struct tty_driver *driver,
 }
 
 /**
- *	tty_driver_remove_tty() - remove a tty from the driver tables
- *	@driver: the driver for the tty
- *	@tty: tty to remove
+ * tty_driver_remove_tty() - remove a tty from the driver tables
+ * @driver: the driver for the tty
+ * @tty: tty to remove
  *
- *	Remvoe a tty object from the driver tables. The tty->index field
- *	will be set by the time this is called.
+ * Remove a tty object from the driver tables. The tty->index field will be set
+ * by the time this is called.
  *
- *	Locking: tty_mutex for now
+ * Locking: tty_mutex for now
  */
 static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty)
 {
@@ -1335,13 +1327,13 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *
 }
 
 /**
- *	tty_reopen()	- fast re-open of an open tty
- *	@tty: the tty to open
+ * tty_reopen()	- fast re-open of an open tty
+ * @tty: the tty to open
  *
- *	Return 0 on success, -errno on error.
- *	Re-opens on master ptys are not allowed and return -EIO.
+ * Re-opens on master ptys are not allowed and return -%EIO.
  *
- *	Locking: Caller must hold tty_lock
+ * Locking: Caller must hold tty_lock
+ * Return: 0 on success, -errno on error.
  */
 static int tty_reopen(struct tty_struct *tty)
 {
@@ -1379,30 +1371,28 @@ static int tty_reopen(struct tty_struct *tty)
 }
 
 /**
- *	tty_init_dev		-	initialise a tty device
- *	@driver: tty driver we are opening a device on
- *	@idx: device index
+ * tty_init_dev		-	initialise a tty device
+ * @driver: tty driver we are opening a device on
+ * @idx: device index
  *
- *	Prepare a tty device. This may not be a "new" clean device but
- *	could also be an active device. The pty drivers require special
- *	handling because of this.
+ * Prepare a tty device. This may not be a "new" clean device but could also be
+ * an active device. The pty drivers require special handling because of this.
  *
- *	Locking:
- *		The function is called under the tty_mutex, which
- *	protects us from the tty struct or driver itself going away.
+ * Locking:
+ *	The function is called under the tty_mutex, which protects us from the
+ *	tty struct or driver itself going away.
  *
- *	On exit the tty device has the line discipline attached and
- *	a reference count of 1. If a pair was created for pty/tty use
- *	and the other was a pty master then it too has a reference count of 1.
+ * On exit the tty device has the line discipline attached and a reference
+ * count of 1. If a pair was created for pty/tty use and the other was a pty
+ * master then it too has a reference count of 1.
  *
- * WSH 06/09/97: Rewritten to remove races and properly clean up after a
- * failed open.  The new code protects the open with a mutex, so it's
- * really quite straightforward.  The mutex locking can probably be
- * relaxed for the (most common) case of reopening a tty.
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed
+ * open. The new code protects the open with a mutex, so it's really quite
+ * straightforward. The mutex locking can probably be relaxed for the (most
+ * common) case of reopening a tty.
  *
- *	Return: returned tty structure
+ * Return: new tty structure
  */
-
 struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
 {
 	struct tty_struct *tty;
@@ -1503,10 +1493,10 @@ void tty_save_termios(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_save_termios);
 
 /**
- *	tty_flush_works		-	flush all works of a tty/pty pair
- *	@tty: tty device to flush works for (or either end of a pty pair)
+ * tty_flush_works	-	flush all works of a tty/pty pair
+ * @tty: tty device to flush works for (or either end of a pty pair)
  *
- *	Sync flush all works belonging to @tty (and the 'other' tty).
+ * Sync flush all works belonging to @tty (and the 'other' tty).
  */
 static void tty_flush_works(struct tty_struct *tty)
 {
@@ -1519,19 +1509,19 @@ static void tty_flush_works(struct tty_struct *tty)
 }
 
 /**
- *	release_one_tty		-	release tty structure memory
- *	@work: work of tty we are obliterating
+ * release_one_tty	-	release tty structure memory
+ * @work: work of tty we are obliterating
  *
- *	Releases memory associated with a tty structure, and clears out the
- *	driver table slots. This function is called when a device is no longer
- *	in use. It also gets called when setup of a device fails.
+ * Releases memory associated with a tty structure, and clears out the
+ * driver table slots. This function is called when a device is no longer
+ * in use. It also gets called when setup of a device fails.
  *
- *	Locking:
- *		takes the file list lock internally when working on the list
- *	of ttys that the driver keeps.
+ * Locking:
+ *	takes the file list lock internally when working on the list of ttys
+ *	that the driver keeps.
  *
- *	This method gets called from a work queue so that the driver private
- *	cleanup ops can sleep (needed for USB at least)
+ * This method gets called from a work queue so that the driver private
+ * cleanup ops can sleep (needed for USB at least)
  */
 static void release_one_tty(struct work_struct *work)
 {
@@ -1568,13 +1558,12 @@ static void queue_release_one_tty(struct kref *kref)
 }
 
 /**
- *	tty_kref_put		-	release a tty kref
- *	@tty: tty device
+ * tty_kref_put		-	release a tty kref
+ * @tty: tty device
  *
- *	Release a reference to a tty device and if need be let the kref
- *	layer destruct the object for us
+ * Release a reference to the @tty device and if need be let the kref layer
+ * destruct the object for us.
  */
-
 void tty_kref_put(struct tty_struct *tty)
 {
 	if (tty)
@@ -1583,18 +1572,17 @@ void tty_kref_put(struct tty_struct *tty)
 EXPORT_SYMBOL(tty_kref_put);
 
 /**
- *	release_tty		-	release tty structure memory
- *	@tty: tty device release
- *	@idx: index of the tty device release
+ * release_tty		-	release tty structure memory
+ * @tty: tty device release
+ * @idx: index of the tty device release
  *
- *	Release both @tty and a possible linked partner (think pty pair),
- *	and decrement the refcount of the backing module.
- *
- *	Locking:
- *		tty_mutex
- *		takes the file list lock internally when working on the list
- *	of ttys that the driver keeps.
+ * Release both @tty and a possible linked partner (think pty pair),
+ * and decrement the refcount of the backing module.
  *
+ * Locking:
+ *	tty_mutex
+ *	takes the file list lock internally when working on the list of ttys
+ *	that the driver keeps.
  */
 static void release_tty(struct tty_struct *tty, int idx)
 {
@@ -1619,12 +1607,12 @@ static void release_tty(struct tty_struct *tty, int idx)
 }
 
 /**
- *	tty_release_checks - check a tty before real release
- *	@tty: tty to check
- *	@idx: index of the tty
+ * tty_release_checks - check a tty before real release
+ * @tty: tty to check
+ * @idx: index of the tty
  *
- *	Performs some paranoid checking before true release of the @tty.
- *	This is a no-op unless TTY_PARANOIA_CHECK is defined.
+ * Performs some paranoid checking before true release of the @tty. This is a
+ * no-op unless %TTY_PARANOIA_CHECK is defined.
  */
 static int tty_release_checks(struct tty_struct *tty, int idx)
 {
@@ -1661,12 +1649,12 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
 }
 
 /**
- *      tty_kclose      -       closes tty opened by tty_kopen
- *      @tty: tty device
+ * tty_kclose      -       closes tty opened by tty_kopen
+ * @tty: tty device
  *
- *      Performs the final steps to release and free a tty device. It is the
- *      same as tty_release_struct except that it also resets TTY_PORT_KOPENED
- *      flag on tty->port.
+ * Performs the final steps to release and free a tty device. It is the same as
+ * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on
+ * @tty->port.
  */
 void tty_kclose(struct tty_struct *tty)
 {
@@ -1691,12 +1679,12 @@ void tty_kclose(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_kclose);
 
 /**
- *	tty_release_struct	-	release a tty struct
- *	@tty: tty device
- *	@idx: index of the tty
+ * tty_release_struct	-	release a tty struct
+ * @tty: tty device
+ * @idx: index of the tty
  *
- *	Performs the final steps to release and free a tty device. It is
- *	roughly the reverse of tty_init_dev.
+ * Performs the final steps to release and free a tty device. It is roughly the
+ * reverse of tty_init_dev().
  */
 void tty_release_struct(struct tty_struct *tty, int idx)
 {
@@ -1720,24 +1708,23 @@ void tty_release_struct(struct tty_struct *tty, int idx)
 EXPORT_SYMBOL_GPL(tty_release_struct);
 
 /**
- *	tty_release		-	vfs callback for close
- *	@inode: inode of tty
- *	@filp: file pointer for handle to tty
+ * tty_release		-	vfs callback for close
+ * @inode: inode of tty
+ * @filp: file pointer for handle to tty
  *
- *	Called the last time each file handle is closed that references
- *	this tty. There may however be several such references.
+ * Called the last time each file handle is closed that references this tty.
+ * There may however be several such references.
  *
- *	Locking:
- *		Takes bkl. See tty_release_dev
+ * Locking:
+ *	Takes BKL. See tty_release_dev().
  *
- * Even releasing the tty structures is a tricky business.. We have
- * to be very careful that the structures are all released at the
- * same time, as interrupts might otherwise get the wrong pointers.
+ * Even releasing the tty structures is a tricky business. We have to be very
+ * careful that the structures are all released at the same time, as interrupts
+ * might otherwise get the wrong pointers.
  *
  * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
  * lead to double frees or releasing memory still in use.
  */
-
 int tty_release(struct inode *inode, struct file *filp)
 {
 	struct tty_struct *tty = file_tty(filp);
@@ -1880,15 +1867,15 @@ int tty_release(struct inode *inode, struct file *filp)
 }
 
 /**
- *	tty_open_current_tty - get locked tty of current task
- *	@device: device number
- *	@filp: file pointer to tty
- *	@return: locked tty of the current task iff @device is /dev/tty
+ * tty_open_current_tty - get locked tty of current task
+ * @device: device number
+ * @filp: file pointer to tty
+ * @return: locked tty of the current task iff @device is /dev/tty
  *
- *	Performs a re-open of the current task's controlling tty.
+ * Performs a re-open of the current task's controlling tty.
  *
- *	We cannot return driver and index like for the other nodes because
- *	devpts will not work then. It expects inodes to be from devpts FS.
+ * We cannot return driver and index like for the other nodes because devpts
+ * will not work then. It expects inodes to be from devpts FS.
  */
 static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
 {
@@ -1916,16 +1903,17 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
 }
 
 /**
- *	tty_lookup_driver - lookup a tty driver for a given device file
- *	@device: device number
- *	@filp: file pointer to tty
- *	@index: index for the device in the @return driver
- *	@return: driver for this inode (with increased refcount)
+ * tty_lookup_driver - lookup a tty driver for a given device file
+ * @device: device number
+ * @filp: file pointer to tty
+ * @index: index for the device in the @return driver
+ *
+ * If returned value is not erroneous, the caller is responsible to decrement
+ * the refcount by tty_driver_kref_put().
  *
- *	If @return is not erroneous, the caller is responsible to decrement the
- *	refcount by tty_driver_kref_put.
+ * Locking: %tty_mutex protects get_tty_driver()
  *
- *	Locking: tty_mutex protects get_tty_driver
+ * Return: driver for this inode (with increased refcount)
  */
 static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
 		int *index)
@@ -2001,19 +1989,18 @@ out:
 }
 
 /**
- *	tty_kopen_exclusive	-	open a tty device for kernel
- *	@device: dev_t of device to open
+ * tty_kopen_exclusive	-	open a tty device for kernel
+ * @device: dev_t of device to open
  *
- *	Opens tty exclusively for kernel. Performs the driver lookup,
- *	makes sure it's not already opened and performs the first-time
- *	tty initialization.
+ * Opens tty exclusively for kernel. Performs the driver lookup, makes sure
+ * it's not already opened and performs the first-time tty initialization.
  *
- *	Returns the locked initialized &tty_struct
+ * Claims the global %tty_mutex to serialize:
+ *  * concurrent first-time tty initialization
+ *  * concurrent tty driver removal w/ lookup
+ *  * concurrent tty removal from driver table
  *
- *	Claims the global tty_mutex to serialize:
- *	  - concurrent first-time tty initialization
- *	  - concurrent tty driver removal w/ lookup
- *	  - concurrent tty removal from driver table
+ * Return: the locked initialized &tty_struct
  */
 struct tty_struct *tty_kopen_exclusive(dev_t device)
 {
@@ -2022,13 +2009,13 @@ struct tty_struct *tty_kopen_exclusive(dev_t device)
 EXPORT_SYMBOL_GPL(tty_kopen_exclusive);
 
 /**
- *	tty_kopen_shared	-	open a tty device for shared in-kernel use
- *	@device: dev_t of device to open
+ * tty_kopen_shared	-	open a tty device for shared in-kernel use
+ * @device: dev_t of device to open
  *
- *	Opens an already existing tty for in-kernel use. Compared to
- *	tty_kopen_exclusive() above it doesn't ensure to be the only user.
+ * Opens an already existing tty for in-kernel use. Compared to
+ * tty_kopen_exclusive() above it doesn't ensure to be the only user.
  *
- *	Locking is identical to tty_kopen() above.
+ * Locking: identical to tty_kopen() above.
  */
 struct tty_struct *tty_kopen_shared(dev_t device)
 {
@@ -2037,19 +2024,20 @@ struct tty_struct *tty_kopen_shared(dev_t device)
 EXPORT_SYMBOL_GPL(tty_kopen_shared);
 
 /**
- *	tty_open_by_driver	-	open a tty device
- *	@device: dev_t of device to open
- *	@filp: file pointer to tty
+ * tty_open_by_driver	-	open a tty device
+ * @device: dev_t of device to open
+ * @filp: file pointer to tty
  *
- *	Performs the driver lookup, checks for a reopen, or otherwise
- *	performs the first-time tty initialization.
+ * Performs the driver lookup, checks for a reopen, or otherwise performs the
+ * first-time tty initialization.
  *
- *	Returns the locked initialized or re-opened &tty_struct
  *
- *	Claims the global tty_mutex to serialize:
- *	  - concurrent first-time tty initialization
- *	  - concurrent tty driver removal w/ lookup
- *	  - concurrent tty removal from driver table
+ * Claims the global tty_mutex to serialize:
+ *  * concurrent first-time tty initialization
+ *  * concurrent tty driver removal w/ lookup
+ *  * concurrent tty removal from driver table
+ *
+ * Return: the locked initialized or re-opened &tty_struct
  */
 static struct tty_struct *tty_open_by_driver(dev_t device,
 					     struct file *filp)
@@ -2104,29 +2092,28 @@ out:
 }
 
 /**
- *	tty_open		-	open a tty device
- *	@inode: inode of device file
- *	@filp: file pointer to tty
+ * tty_open	-	open a tty device
+ * @inode: inode of device file
+ * @filp: file pointer to tty
  *
- *	tty_open and tty_release keep up the tty count that contains the
- *	number of opens done on a tty. We cannot use the inode-count, as
- *	different inodes might point to the same tty.
+ * tty_open() and tty_release() keep up the tty count that contains the number
+ * of opens done on a tty. We cannot use the inode-count, as different inodes
+ * might point to the same tty.
  *
- *	Open-counting is needed for pty masters, as well as for keeping
- *	track of serial lines: DTR is dropped when the last close happens.
- *	(This is not done solely through tty->count, now.  - Ted 1/27/92)
+ * Open-counting is needed for pty masters, as well as for keeping track of
+ * serial lines: DTR is dropped when the last close happens.
+ * (This is not done solely through tty->count, now.  - Ted 1/27/92)
  *
- *	The termios state of a pty is reset on first open so that
- *	settings don't persist across reuse.
+ * The termios state of a pty is reset on the first open so that settings don't
+ * persist across reuse.
  *
- *	Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
- *		 tty->count should protect the rest.
- *		 ->siglock protects ->signal/->sighand
+ * Locking:
+ *  * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev().
+ *  * @tty->count should protect the rest.
+ *  * ->siglock protects ->signal/->sighand
  *
- *	Note: the tty_unlock/lock cases without a ref are only safe due to
- *	tty_mutex
+ * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex
  */
-
 static int tty_open(struct inode *inode, struct file *filp)
 {
 	struct tty_struct *tty;
@@ -2198,19 +2185,17 @@ retry_open:
 }
 
 
-
 /**
- *	tty_poll	-	check tty status
- *	@filp: file being polled
- *	@wait: poll wait structures to update
+ * tty_poll	-	check tty status
+ * @filp: file being polled
+ * @wait: poll wait structures to update
  *
- *	Call the line discipline polling method to obtain the poll
- *	status of the device.
+ * Call the line discipline polling method to obtain the poll status of the
+ * device.
  *
- *	Locking: locks called line discipline but ldisc poll method
- *	may be re-entered freely by other callers.
+ * Locking: locks called line discipline but ldisc poll method may be
+ * re-entered freely by other callers.
  */
-
 static __poll_t tty_poll(struct file *filp, poll_table *wait)
 {
 	struct tty_struct *tty = file_tty(filp);
@@ -2278,20 +2263,18 @@ static int tty_fasync(int fd, struct file *filp, int on)
 }
 
 /**
- *	tiocsti			-	fake input character
- *	@tty: tty to fake input into
- *	@p: pointer to character
+ * tiocsti		-	fake input character
+ * @tty: tty to fake input into
+ * @p: pointer to character
  *
- *	Fake input to a tty device. Does the necessary locking and
- *	input management.
+ * Fake input to a tty device. Does the necessary locking and input management.
  *
- *	FIXME: does not honour flow control ??
+ * FIXME: does not honour flow control ??
  *
- *	Locking:
- *		Called functions take tty_ldiscs_lock
- *		current->signal->tty check is safe without locks
+ * Locking:
+ *  * Called functions take tty_ldiscs_lock
+ *  * current->signal->tty check is safe without locks
  */
-
 static int tiocsti(struct tty_struct *tty, char __user *p)
 {
 	char ch, mbz = 0;
@@ -2314,16 +2297,15 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
 }
 
 /**
- *	tiocgwinsz		-	implement window query ioctl
- *	@tty: tty
- *	@arg: user buffer for result
+ * tiocgwinsz		-	implement window query ioctl
+ * @tty: tty
+ * @arg: user buffer for result
  *
- *	Copies the kernel idea of the window size into the user buffer.
+ * Copies the kernel idea of the window size into the user buffer.
  *
- *	Locking: tty->winsize_mutex is taken to ensure the winsize data
- *		is consistent.
+ * Locking: @tty->winsize_mutex is taken to ensure the winsize data is
+ * consistent.
  */
-
 static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 {
 	int err;
@@ -2336,14 +2318,13 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 }
 
 /**
- *	tty_do_resize		-	resize event
- *	@tty: tty being resized
- *	@ws: new dimensions
+ * tty_do_resize	-	resize event
+ * @tty: tty being resized
+ * @ws: new dimensions
  *
- *	Update the termios variables and send the necessary signals to
- *	peform a terminal resize correctly
+ * Update the termios variables and send the necessary signals to peform a
+ * terminal resize correctly.
  */
-
 int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
 {
 	struct pid *pgrp;
@@ -2367,20 +2348,19 @@ done:
 EXPORT_SYMBOL(tty_do_resize);
 
 /**
- *	tiocswinsz		-	implement window size set ioctl
- *	@tty: tty side of tty
- *	@arg: user buffer for result
+ * tiocswinsz		-	implement window size set ioctl
+ * @tty: tty side of tty
+ * @arg: user buffer for result
  *
- *	Copies the user idea of the window size to the kernel. Traditionally
- *	this is just advisory information but for the Linux console it
- *	actually has driver level meaning and triggers a VC resize.
+ * Copies the user idea of the window size to the kernel. Traditionally this is
+ * just advisory information but for the Linux console it actually has driver
+ * level meaning and triggers a VC resize.
  *
- *	Locking:
- *		Driver dependent. The default do_resize method takes the
- *	tty termios mutex and ctrl.lock. The console takes its own lock
- *	then calls into the default method.
+ * Locking:
+ *	Driver dependent. The default do_resize method takes the tty termios
+ *	mutex and ctrl.lock. The console takes its own lock then calls into the
+ *	default method.
  */
-
 static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
 {
 	struct winsize tmp_ws;
@@ -2395,14 +2375,13 @@ static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
 }
 
 /**
- *	tioccons	-	allow admin to move logical console
- *	@file: the file to become console
+ * tioccons	-	allow admin to move logical console
+ * @file: the file to become console
  *
- *	Allow the administrator to move the redirected console device
+ * Allow the administrator to move the redirected console device.
  *
- *	Locking: uses redirect_lock to guard the redirect information
+ * Locking: uses redirect_lock to guard the redirect information
  */
-
 static int tioccons(struct file *file)
 {
 	if (!capable(CAP_SYS_ADMIN))
@@ -2435,15 +2414,14 @@ static int tioccons(struct file *file)
 }
 
 /**
- *	tiocsetd	-	set line discipline
- *	@tty: tty device
- *	@p: pointer to user data
+ * tiocsetd	-	set line discipline
+ * @tty: tty device
+ * @p: pointer to user data
  *
- *	Set the line discipline according to user request.
+ * Set the line discipline according to user request.
  *
- *	Locking: see tty_set_ldisc, this function is just a helper
+ * Locking: see tty_set_ldisc(), this function is just a helper
  */
-
 static int tiocsetd(struct tty_struct *tty, int __user *p)
 {
 	int disc;
@@ -2458,16 +2436,15 @@ static int tiocsetd(struct tty_struct *tty, int __user *p)
 }
 
 /**
- *	tiocgetd	-	get line discipline
- *	@tty: tty device
- *	@p: pointer to user data
+ * tiocgetd	-	get line discipline
+ * @tty: tty device
+ * @p: pointer to user data
  *
- *	Retrieves the line discipline id directly from the ldisc.
+ * Retrieves the line discipline id directly from the ldisc.
  *
- *	Locking: waits for ldisc reference (in case the line discipline
- *		is changing or the tty is being hungup)
+ * Locking: waits for ldisc reference (in case the line discipline is changing
+ * or the @tty is being hungup)
  */
-
 static int tiocgetd(struct tty_struct *tty, int __user *p)
 {
 	struct tty_ldisc *ld;
@@ -2482,18 +2459,16 @@ static int tiocgetd(struct tty_struct *tty, int __user *p)
 }
 
 /**
- *	send_break	-	performed time break
- *	@tty: device to break on
- *	@duration: timeout in mS
- *
- *	Perform a timed break on hardware that lacks its own driver level
- *	timed break functionality.
+ * send_break	-	performed time break
+ * @tty: device to break on
+ * @duration: timeout in mS
  *
- *	Locking:
- *		atomic_write_lock serializes
+ * Perform a timed break on hardware that lacks its own driver level timed
+ * break functionality.
  *
+ * Locking:
+ *	@tty->atomic_write_lock serializes
  */
-
 static int send_break(struct tty_struct *tty, unsigned int duration)
 {
 	int retval;
@@ -2522,16 +2497,15 @@ out:
 }
 
 /**
- *	tty_tiocmget		-	get modem status
- *	@tty: tty device
- *	@p: pointer to result
+ * tty_tiocmget		-	get modem status
+ * @tty: tty device
+ * @p: pointer to result
  *
- *	Obtain the modem status bits from the tty driver if the feature
- *	is supported. Return -ENOTTY if it is not available.
+ * Obtain the modem status bits from the tty driver if the feature is
+ * supported. Return -%ENOTTY if it is not available.
  *
- *	Locking: none (up to the driver)
+ * Locking: none (up to the driver)
  */
-
 static int tty_tiocmget(struct tty_struct *tty, int __user *p)
 {
 	int retval = -ENOTTY;
@@ -2546,17 +2520,16 @@ static int tty_tiocmget(struct tty_struct *tty, int __user *p)
 }
 
 /**
- *	tty_tiocmset		-	set modem status
- *	@tty: tty device
- *	@cmd: command - clear bits, set bits or set all
- *	@p: pointer to desired bits
+ * tty_tiocmset		-	set modem status
+ * @tty: tty device
+ * @cmd: command - clear bits, set bits or set all
+ * @p: pointer to desired bits
  *
- *	Set the modem status bits from the tty driver if the feature
- *	is supported. Return -ENOTTY if it is not available.
+ * Set the modem status bits from the tty driver if the feature
+ * is supported. Return -%ENOTTY if it is not available.
  *
- *	Locking: none (up to the driver)
+ * Locking: none (up to the driver)
  */
-
 static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd,
 	     unsigned __user *p)
 {
@@ -2588,13 +2561,13 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd,
 }
 
 /**
- *	tty_get_icount		-	get tty statistics
- *	@tty: tty device
- *	@icount: output parameter
+ * tty_get_icount	-	get tty statistics
+ * @tty: tty device
+ * @icount: output parameter
  *
- *	Gets a copy of the tty's icount statistics.
+ * Gets a copy of the @tty's icount statistics.
  *
- *	Locking: none (up to the driver)
+ * Locking: none (up to the driver)
  */
 int tty_get_icount(struct tty_struct *tty,
 		   struct serial_icounter_struct *icount)
@@ -2811,7 +2784,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		return hung_up_tty_ioctl(file, cmd, arg);
 	retval = -EINVAL;
 	if (ld->ops->ioctl) {
-		retval = ld->ops->ioctl(tty, file, cmd, arg);
+		retval = ld->ops->ioctl(tty, cmd, arg);
 		if (retval == -ENOIOCTLCMD)
 			retval = -ENOTTY;
 	}
@@ -2990,10 +2963,10 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 	if (!ld)
 		return hung_up_tty_compat_ioctl(file, cmd, arg);
 	if (ld->ops->compat_ioctl)
-		retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
+		retval = ld->ops->compat_ioctl(tty, cmd, arg);
 	if (retval == -ENOIOCTLCMD && ld->ops->ioctl)
-		retval = ld->ops->ioctl(tty, file,
-				(unsigned long)compat_ptr(cmd), arg);
+		retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd),
+				arg);
 	tty_ldisc_deref(ld);
 
 	return retval;
@@ -3028,17 +3001,11 @@ static int this_tty(const void *t, struct file *file, unsigned fd)
  */
 void __do_SAK(struct tty_struct *tty)
 {
-#ifdef TTY_SOFT_SAK
-	tty_hangup(tty);
-#else
 	struct task_struct *g, *p;
 	struct pid *session;
-	int		i;
+	int i;
 	unsigned long flags;
 
-	if (!tty)
-		return;
-
 	spin_lock_irqsave(&tty->ctrl.lock, flags);
 	session = get_pid(tty->ctrl.session);
 	spin_unlock_irqrestore(&tty->ctrl.lock, flags);
@@ -3060,7 +3027,8 @@ void __do_SAK(struct tty_struct *tty)
 		if (p->signal->tty == tty) {
 			tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n",
 				   task_pid_nr(p), p->comm);
-			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID);
+			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
+					PIDTYPE_SID);
 			continue;
 		}
 		task_lock(p);
@@ -3068,13 +3036,13 @@ void __do_SAK(struct tty_struct *tty)
 		if (i != 0) {
 			tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n",
 				   task_pid_nr(p), p->comm, i - 1);
-			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID);
+			group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
+					PIDTYPE_SID);
 		}
 		task_unlock(p);
 	} while_each_thread(g, p);
 	read_unlock(&tasklist_lock);
 	put_pid(session);
-#endif
 }
 
 static void do_SAK_work(struct work_struct *work)
@@ -3107,14 +3075,15 @@ static struct device *tty_get_device(struct tty_struct *tty)
 }
 
 
-/*
- *	alloc_tty_struct
+/**
+ * alloc_tty_struct - allocate a new tty
+ * @driver: driver which will handle the returned tty
+ * @idx: minor of the tty
  *
- *	This subroutine allocates and initializes a tty structure.
+ * This subroutine allocates and initializes a tty structure.
  *
- *	Locking: none - tty in question is not exposed at this point
+ * Locking: none - @tty in question is not exposed at this point
  */
-
 struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
 {
 	struct tty_struct *tty;
@@ -3156,17 +3125,18 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
 }
 
 /**
- *	tty_put_char	-	write one character to a tty
- *	@tty: tty
- *	@ch: character
+ * tty_put_char	- write one character to a tty
+ * @tty: tty
+ * @ch: character to write
+ *
+ * Write one byte to the @tty using the provided @tty->ops->put_char() method
+ * if present.
  *
- *	Write one byte to the tty using the provided put_char method
- *	if present. Returns the number of characters successfully output.
+ * Note: the specific put_char operation in the driver layer may go
+ * away soon. Don't call it directly, use this method
  *
- *	Note: the specific put_char operation in the driver layer may go
- *	away soon. Don't call it directly, use this method
+ * Return: the number of characters successfully output.
  */
-
 int tty_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	if (tty->ops->put_char)
@@ -3195,24 +3165,23 @@ static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
 }
 
 /**
- *	tty_register_device - register a tty device
- *	@driver: the tty driver that describes the tty device
- *	@index: the index in the tty driver for this tty device
- *	@device: a struct device that is associated with this tty device.
- *		This field is optional, if there is no known struct device
- *		for this tty device it can be set to NULL safely.
+ * tty_register_device - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ *	This field is optional, if there is no known struct device
+ *	for this tty device it can be set to NULL safely.
  *
- *	Returns a pointer to the struct device for this tty device
- *	(or ERR_PTR(-EFOO) on error).
+ * This call is required to be made to register an individual tty device
+ * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set.  If
+ * that bit is not set, this function should not be called by a tty
+ * driver.
  *
- *	This call is required to be made to register an individual tty device
- *	if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set.  If
- *	that bit is not set, this function should not be called by a tty
- *	driver.
+ * Locking: ??
  *
- *	Locking: ??
+ * Return: A pointer to the struct device for this tty device (or
+ * ERR_PTR(-EFOO) on error).
  */
-
 struct device *tty_register_device(struct tty_driver *driver, unsigned index,
 				   struct device *device)
 {
@@ -3227,24 +3196,23 @@ static void tty_device_create_release(struct device *dev)
 }
 
 /**
- *	tty_register_device_attr - register a tty device
- *	@driver: the tty driver that describes the tty device
- *	@index: the index in the tty driver for this tty device
- *	@device: a struct device that is associated with this tty device.
- *		This field is optional, if there is no known struct device
- *		for this tty device it can be set to NULL safely.
- *	@drvdata: Driver data to be set to device.
- *	@attr_grp: Attribute group to be set on device.
+ * tty_register_device_attr - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ *	This field is optional, if there is no known struct device
+ *	for this tty device it can be set to %NULL safely.
+ * @drvdata: Driver data to be set to device.
+ * @attr_grp: Attribute group to be set on device.
  *
- *	Returns a pointer to the struct device for this tty device
- *	(or ERR_PTR(-EFOO) on error).
+ * This call is required to be made to register an individual tty device if the
+ * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is
+ * not set, this function should not be called by a tty driver.
  *
- *	This call is required to be made to register an individual tty device
- *	if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set.  If
- *	that bit is not set, this function should not be called by a tty
- *	driver.
+ * Locking: ??
  *
- *	Locking: ??
+ * Return: A pointer to the struct device for this tty device (or
+ * ERR_PTR(-EFOO) on error).
  */
 struct device *tty_register_device_attr(struct tty_driver *driver,
 				   unsigned index, struct device *device,
@@ -3317,16 +3285,15 @@ err_put:
 EXPORT_SYMBOL_GPL(tty_register_device_attr);
 
 /**
- *	tty_unregister_device - unregister a tty device
- *	@driver: the tty driver that describes the tty device
- *	@index: the index in the tty driver for this tty device
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
  *
- *	If a tty device is registered with a call to tty_register_device() then
- *	this function must be called when the tty device is gone.
+ * If a tty device is registered with a call to tty_register_device() then
+ * this function must be called when the tty device is gone.
  *
- *	Locking: ??
+ * Locking: ??
  */
-
 void tty_unregister_device(struct tty_driver *driver, unsigned index)
 {
 	device_destroy(tty_class,
@@ -3342,10 +3309,10 @@ EXPORT_SYMBOL(tty_unregister_device);
  * __tty_alloc_driver -- allocate tty driver
  * @lines: count of lines this driver can handle at most
  * @owner: module which is responsible for this driver
- * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
+ * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags
  *
  * This should not be called directly, some of the provided macros should be
- * used instead. Use IS_ERR and friends on @retval.
+ * used instead. Use IS_ERR() and friends on @retval.
  */
 struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
 		unsigned long flags)
@@ -3432,13 +3399,22 @@ static void destruct_tty_driver(struct kref *kref)
 	kfree(driver);
 }
 
+/**
+ * tty_driver_kref_put -- drop a reference to a tty driver
+ * @driver: driver of which to drop the reference
+ *
+ * The final put will destroy and free up the driver.
+ */
 void tty_driver_kref_put(struct tty_driver *driver)
 {
 	kref_put(&driver->kref, destruct_tty_driver);
 }
 EXPORT_SYMBOL(tty_driver_kref_put);
 
-/*
+/**
+ * tty_register_driver -- register a tty driver
+ * @driver: driver to register
+ *
  * Called by a tty driver to register itself.
  */
 int tty_register_driver(struct tty_driver *driver)
@@ -3500,7 +3476,10 @@ err:
 }
 EXPORT_SYMBOL(tty_register_driver);
 
-/*
+/**
+ * tty_unregister_driver -- unregister a tty driver
+ * @driver: driver to unregister
+ *
  * Called by a tty driver to unregister itself.
  */
 void tty_unregister_driver(struct tty_driver *driver)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 3e4e0b20b4bb..776d8a62f77c 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -47,17 +47,14 @@ static DEFINE_RAW_SPINLOCK(tty_ldiscs_lock);
 static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
 
 /**
- *	tty_register_ldisc	-	install a line discipline
- *	@new_ldisc: pointer to the ldisc object
+ * tty_register_ldisc	-	install a line discipline
+ * @new_ldisc: pointer to the ldisc object
  *
- *	Installs a new line discipline into the kernel. The discipline
- *	is set up as unreferenced and then made available to the kernel
- *	from this point onwards.
+ * Installs a new line discipline into the kernel. The discipline is set up as
+ * unreferenced and then made available to the kernel from this point onwards.
  *
- *	Locking:
- *		takes tty_ldiscs_lock to guard against ldisc races
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
  */
-
 int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
 {
 	unsigned long flags;
@@ -75,14 +72,13 @@ int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
 EXPORT_SYMBOL(tty_register_ldisc);
 
 /**
- *	tty_unregister_ldisc	-	unload a line discipline
- *	@ldisc: ldisc number
+ * tty_unregister_ldisc	-	unload a line discipline
+ * @ldisc: ldisc number
  *
- *	Remove a line discipline from the kernel providing it is not
- *	currently in use.
+ * Remove a line discipline from the kernel providing it is not currently in
+ * use.
  *
- *	Locking:
- *		takes tty_ldiscs_lock to guard against ldisc races
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
  */
 
 void tty_unregister_ldisc(struct tty_ldisc_ops *ldisc)
@@ -122,27 +118,25 @@ static void put_ldops(struct tty_ldisc_ops *ldops)
 }
 
 static int tty_ldisc_autoload = IS_BUILTIN(CONFIG_LDISC_AUTOLOAD);
+
 /**
- *	tty_ldisc_get		-	take a reference to an ldisc
- *	@tty: tty device
- *	@disc: ldisc number
- *
- *	Takes a reference to a line discipline. Deals with refcounts and
- *	module locking counts.
- *
- *	Returns: -EINVAL if the discipline index is not [N_TTY..NR_LDISCS] or
- *			 if the discipline is not registered
- *		 -EAGAIN if request_module() failed to load or register the
- *			 discipline
- *		 -ENOMEM if allocation failure
- *
- *		 Otherwise, returns a pointer to the discipline and bumps the
- *		 ref count
- *
- *	Locking:
- *		takes tty_ldiscs_lock to guard against ldisc races
+ * tty_ldisc_get	-	take a reference to an ldisc
+ * @tty: tty device
+ * @disc: ldisc number
+ *
+ * Takes a reference to a line discipline. Deals with refcounts and module
+ * locking counts. If the discipline is not available, its module loaded, if
+ * possible.
+ *
+ * Returns:
+ * * -%EINVAL if the discipline index is not [%N_TTY .. %NR_LDISCS] or if the
+ *   discipline is not registered
+ * * -%EAGAIN if request_module() failed to load or register the discipline
+ * * -%ENOMEM if allocation failure
+ * * Otherwise, returns a pointer to the discipline and bumps the ref count
+ *
+ * Locking: takes %tty_ldiscs_lock to guard against ldisc races
  */
-
 static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
 {
 	struct tty_ldisc *ld;
@@ -176,10 +170,11 @@ static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
 	return ld;
 }
 
-/*
- *	tty_ldisc_put		-	release the ldisc
+/**
+ * tty_ldisc_put	-	release the ldisc
+ * @ld: lisdsc to release
  *
- *	Complement of tty_ldisc_get().
+ * Complement of tty_ldisc_get().
  */
 static void tty_ldisc_put(struct tty_ldisc *ld)
 {
@@ -226,25 +221,22 @@ const struct seq_operations tty_ldiscs_seq_ops = {
 };
 
 /**
- *	tty_ldisc_ref_wait	-	wait for the tty ldisc
- *	@tty: tty device
+ * tty_ldisc_ref_wait	-	wait for the tty ldisc
+ * @tty: tty device
  *
- *	Dereference the line discipline for the terminal and take a
- *	reference to it. If the line discipline is in flux then
- *	wait patiently until it changes.
+ * Dereference the line discipline for the terminal and take a reference to it.
+ * If the line discipline is in flux then wait patiently until it changes.
  *
- *	Returns: NULL if the tty has been hungup and not re-opened with
- *		 a new file descriptor, otherwise valid ldisc reference
+ * Returns: %NULL if the tty has been hungup and not re-opened with a new file
+ * descriptor, otherwise valid ldisc reference
  *
- *	Note 1: Must not be called from an IRQ/timer context. The caller
- *	must also be careful not to hold other locks that will deadlock
- *	against a discipline change, such as an existing ldisc reference
- *	(which we check for)
+ * Note 1: Must not be called from an IRQ/timer context. The caller must also
+ * be careful not to hold other locks that will deadlock against a discipline
+ * change, such as an existing ldisc reference (which we check for).
  *
- *	Note 2: a file_operations routine (read/poll/write) should use this
- *	function to wait for any ldisc lifetime events to finish.
+ * Note 2: a file_operations routine (read/poll/write) should use this function
+ * to wait for any ldisc lifetime events to finish.
  */
-
 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld;
@@ -258,14 +250,13 @@ struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
 
 /**
- *	tty_ldisc_ref		-	get the tty ldisc
- *	@tty: tty device
+ * tty_ldisc_ref	-	get the tty ldisc
+ * @tty: tty device
  *
- *	Dereference the line discipline for the terminal and take a
- *	reference to it. If the line discipline is in flux then
- *	return NULL. Can be called from IRQ and timer functions.
+ * Dereference the line discipline for the terminal and take a reference to it.
+ * If the line discipline is in flux then return %NULL. Can be called from IRQ
+ * and timer functions.
  */
-
 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld = NULL;
@@ -280,13 +271,12 @@ struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_ldisc_ref);
 
 /**
- *	tty_ldisc_deref		-	free a tty ldisc reference
- *	@ld: reference to free up
+ * tty_ldisc_deref	-	free a tty ldisc reference
+ * @ld: reference to free up
  *
- *	Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
- *	be called in IRQ context.
+ * Undoes the effect of tty_ldisc_ref() or tty_ldisc_ref_wait(). May be called
+ * in IRQ context.
  */
-
 void tty_ldisc_deref(struct tty_ldisc *ld)
 {
 	ldsem_up_read(&ld->tty->ldisc_sem);
@@ -386,13 +376,12 @@ static void tty_ldisc_unlock_pair(struct tty_struct *tty,
 }
 
 /**
- *	tty_ldisc_flush	-	flush line discipline queue
- *	@tty: tty
+ * tty_ldisc_flush		-	flush line discipline queue
+ * @tty: tty to flush ldisc for
  *
- *	Flush the line discipline queue (if any) and the tty flip buffers
- *	for this tty.
+ * Flush the line discipline queue (if any) and the tty flip buffers for this
+ * @tty.
  */
-
 void tty_ldisc_flush(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld = tty_ldisc_ref(tty);
@@ -404,21 +393,18 @@ void tty_ldisc_flush(struct tty_struct *tty)
 EXPORT_SYMBOL_GPL(tty_ldisc_flush);
 
 /**
- *	tty_set_termios_ldisc		-	set ldisc field
- *	@tty: tty structure
- *	@disc: line discipline number
+ * tty_set_termios_ldisc	-	set ldisc field
+ * @tty: tty structure
+ * @disc: line discipline number
  *
- *	This is probably overkill for real world processors but
- *	they are not on hot paths so a little discipline won't do
- *	any harm.
+ * This is probably overkill for real world processors but they are not on hot
+ * paths so a little discipline won't do any harm.
  *
- *	The line discipline-related tty_struct fields are reset to
- *	prevent the ldisc driver from re-using stale information for
- *	the new ldisc instance.
+ * The line discipline-related tty_struct fields are reset to prevent the ldisc
+ * driver from re-using stale information for the new ldisc instance.
  *
- *	Locking: takes termios_rwsem
+ * Locking: takes termios_rwsem
  */
-
 static void tty_set_termios_ldisc(struct tty_struct *tty, int disc)
 {
 	down_write(&tty->termios_rwsem);
@@ -430,16 +416,14 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int disc)
 }
 
 /**
- *	tty_ldisc_open		-	open a line discipline
- *	@tty: tty we are opening the ldisc on
- *	@ld: discipline to open
+ * tty_ldisc_open		-	open a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to open
  *
- *	A helper opening method. Also a convenient debugging and check
- *	point.
+ * A helper opening method. Also a convenient debugging and check point.
  *
- *	Locking: always called with BTM already held.
+ * Locking: always called with BTM already held.
  */
-
 static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
 {
 	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
@@ -457,14 +441,12 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
 }
 
 /**
- *	tty_ldisc_close		-	close a line discipline
- *	@tty: tty we are opening the ldisc on
- *	@ld: discipline to close
+ * tty_ldisc_close		-	close a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to close
  *
- *	A helper close method. Also a convenient debugging and check
- *	point.
+ * A helper close method. Also a convenient debugging and check point.
  */
-
 static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
 {
 	lockdep_assert_held_write(&tty->ldisc_sem);
@@ -476,14 +458,13 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
 }
 
 /**
- *	tty_ldisc_failto	-	helper for ldisc failback
- *	@tty: tty to open the ldisc on
- *	@ld: ldisc we are trying to fail back to
+ * tty_ldisc_failto	-	helper for ldisc failback
+ * @tty: tty to open the ldisc on
+ * @ld: ldisc we are trying to fail back to
  *
- *	Helper to try and recover a tty when switching back to the old
- *	ldisc fails and we need something attached.
+ * Helper to try and recover a tty when switching back to the old ldisc fails
+ * and we need something attached.
  */
-
 static int tty_ldisc_failto(struct tty_struct *tty, int ld)
 {
 	struct tty_ldisc *disc = tty_ldisc_get(tty, ld);
@@ -501,14 +482,13 @@ static int tty_ldisc_failto(struct tty_struct *tty, int ld)
 }
 
 /**
- *	tty_ldisc_restore	-	helper for tty ldisc change
- *	@tty: tty to recover
- *	@old: previous ldisc
+ * tty_ldisc_restore	-	helper for tty ldisc change
+ * @tty: tty to recover
+ * @old: previous ldisc
  *
- *	Restore the previous line discipline or N_TTY when a line discipline
- *	change fails due to an open error
+ * Restore the previous line discipline or %N_TTY when a line discipline change
+ * fails due to an open error
  */
-
 static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
 {
 	/* There is an outstanding reference here so this is safe */
@@ -528,16 +508,15 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
 }
 
 /**
- *	tty_set_ldisc		-	set line discipline
- *	@tty: the terminal to set
- *	@disc: the line discipline number
- *
- *	Set the discipline of a tty line. Must be called from a process
- *	context. The ldisc change logic has to protect itself against any
- *	overlapping ldisc change (including on the other end of pty pairs),
- *	the close of one side of a tty/pty pair, and eventually hangup.
+ * tty_set_ldisc		-	set line discipline
+ * @tty: the terminal to set
+ * @disc: the line discipline number
+ *
+ * Set the discipline of a tty line. Must be called from a process context. The
+ * ldisc change logic has to protect itself against any overlapping ldisc
+ * change (including on the other end of pty pairs), the close of one side of a
+ * tty/pty pair, and eventually hangup.
  */
-
 int tty_set_ldisc(struct tty_struct *tty, int disc)
 {
 	int retval;
@@ -613,10 +592,10 @@ err:
 EXPORT_SYMBOL_GPL(tty_set_ldisc);
 
 /**
- *	tty_ldisc_kill	-	teardown ldisc
- *	@tty: tty being released
+ * tty_ldisc_kill	-	teardown ldisc
+ * @tty: tty being released
  *
- *	Perform final close of the ldisc and reset tty->ldisc
+ * Perform final close of the ldisc and reset @tty->ldisc
  */
 static void tty_ldisc_kill(struct tty_struct *tty)
 {
@@ -633,12 +612,11 @@ static void tty_ldisc_kill(struct tty_struct *tty)
 }
 
 /**
- *	tty_reset_termios	-	reset terminal state
- *	@tty: tty to reset
+ * tty_reset_termios	-	reset terminal state
+ * @tty: tty to reset
  *
- *	Restore a terminal to the driver default state.
+ * Restore a terminal to the driver default state.
  */
-
 static void tty_reset_termios(struct tty_struct *tty)
 {
 	down_write(&tty->termios_rwsem);
@@ -650,19 +628,17 @@ static void tty_reset_termios(struct tty_struct *tty)
 
 
 /**
- *	tty_ldisc_reinit	-	reinitialise the tty ldisc
- *	@tty: tty to reinit
- *	@disc: line discipline to reinitialize
+ * tty_ldisc_reinit	-	reinitialise the tty ldisc
+ * @tty: tty to reinit
+ * @disc: line discipline to reinitialize
  *
- *	Completely reinitialize the line discipline state, by closing the
- *	current instance, if there is one, and opening a new instance. If
- *	an error occurs opening the new non-N_TTY instance, the instance
- *	is dropped and tty->ldisc reset to NULL. The caller can then retry
- *	with N_TTY instead.
+ * Completely reinitialize the line discipline state, by closing the current
+ * instance, if there is one, and opening a new instance. If an error occurs
+ * opening the new non-%N_TTY instance, the instance is dropped and @tty->ldisc
+ * reset to %NULL. The caller can then retry with %N_TTY instead.
  *
- *	Returns 0 if successful, otherwise error code < 0
+ * Returns: 0 if successful, otherwise error code < 0
  */
-
 int tty_ldisc_reinit(struct tty_struct *tty, int disc)
 {
 	struct tty_ldisc *ld;
@@ -692,21 +668,20 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc)
 }
 
 /**
- *	tty_ldisc_hangup		-	hangup ldisc reset
- *	@tty: tty being hung up
- *	@reinit: whether to re-initialise the tty
+ * tty_ldisc_hangup	-	hangup ldisc reset
+ * @tty: tty being hung up
+ * @reinit: whether to re-initialise the tty
  *
- *	Some tty devices reset their termios when they receive a hangup
- *	event. In that situation we must also switch back to N_TTY properly
- *	before we reset the termios data.
+ * Some tty devices reset their termios when they receive a hangup event. In
+ * that situation we must also switch back to %N_TTY properly before we reset
+ * the termios data.
  *
- *	Locking: We can take the ldisc mutex as the rest of the code is
- *	careful to allow for this.
+ * Locking: We can take the ldisc mutex as the rest of the code is careful to
+ * allow for this.
  *
- *	In the pty pair case this occurs in the close() path of the
- *	tty itself so we must be careful about locking rules.
+ * In the pty pair case this occurs in the close() path of the tty itself so we
+ * must be careful about locking rules.
  */
-
 void tty_ldisc_hangup(struct tty_struct *tty, bool reinit)
 {
 	struct tty_ldisc *ld;
@@ -752,15 +727,14 @@ void tty_ldisc_hangup(struct tty_struct *tty, bool reinit)
 }
 
 /**
- *	tty_ldisc_setup			-	open line discipline
- *	@tty: tty being shut down
- *	@o_tty: pair tty for pty/tty pairs
+ * tty_ldisc_setup	-	open line discipline
+ * @tty: tty being shut down
+ * @o_tty: pair tty for pty/tty pairs
  *
- *	Called during the initial open of a tty/pty pair in order to set up the
- *	line disciplines and bind them to the tty. This has no locking issues
- *	as the device isn't yet active.
+ * Called during the initial open of a tty/pty pair in order to set up the line
+ * disciplines and bind them to the @tty. This has no locking issues as the
+ * device isn't yet active.
  */
-
 int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
 {
 	int retval = tty_ldisc_open(tty, tty->ldisc);
@@ -783,13 +757,12 @@ int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
 }
 
 /**
- *	tty_ldisc_release		-	release line discipline
- *	@tty: tty being shut down (or one end of pty pair)
+ * tty_ldisc_release	-	release line discipline
+ * @tty: tty being shut down (or one end of pty pair)
  *
- *	Called during the final close of a tty or a pty pair in order to shut
- *	down the line discpline layer. On exit, each tty's ldisc is NULL.
+ * Called during the final close of a tty or a pty pair in order to shut down
+ * the line discpline layer. On exit, each tty's ldisc is %NULL.
  */
-
 void tty_ldisc_release(struct tty_struct *tty)
 {
 	struct tty_struct *o_tty = tty->link;
@@ -814,13 +787,12 @@ void tty_ldisc_release(struct tty_struct *tty)
 }
 
 /**
- *	tty_ldisc_init		-	ldisc setup for new tty
- *	@tty: tty being allocated
+ * tty_ldisc_init	-	ldisc setup for new tty
+ * @tty: tty being allocated
  *
- *	Set up the line discipline objects for a newly allocated tty. Note that
- *	the tty structure is not completely set up when this call is made.
+ * Set up the line discipline objects for a newly allocated tty. Note that the
+ * tty structure is not completely set up when this call is made.
  */
-
 int tty_ldisc_init(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld = tty_ldisc_get(tty, N_TTY);
@@ -832,11 +804,11 @@ int tty_ldisc_init(struct tty_struct *tty)
 }
 
 /**
- *	tty_ldisc_deinit	-	ldisc cleanup for new tty
- *	@tty: tty that was allocated recently
+ * tty_ldisc_deinit	-	ldisc cleanup for new tty
+ * @tty: tty that was allocated recently
  *
- *	The tty structure must not becompletely set up (tty_ldisc_setup) when
- *      this call is made.
+ * The tty structure must not be completely set up (tty_ldisc_setup()) when
+ * this call is made.
  */
 void tty_ldisc_deinit(struct tty_struct *tty)
 {
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index ce8291053af3..3be428c16260 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -163,7 +163,7 @@ down_read_failed(struct ld_semaphore *sem, long count, long timeout)
 
 	/*
 	 * Try to reverse the lock attempt but if the count has changed
-	 * so that reversing fails, check if there are are no waiters,
+	 * so that reversing fails, check if there are no waiters,
 	 * and early-out if not
 	 */
 	do {
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 2f1061a9d926..7709ce655f44 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -59,6 +59,15 @@ const struct tty_port_client_operations tty_port_default_client_ops = {
 };
 EXPORT_SYMBOL_GPL(tty_port_default_client_ops);
 
+/**
+ * tty_port_init -- initialize tty_port
+ * @port: tty_port to initialize
+ *
+ * Initializes the state of struct tty_port. When a port was initialized using
+ * this function, one has to destroy the port by tty_port_destroy(). Either
+ * indirectly by using &tty_port refcounting (tty_port_put()) or directly if
+ * refcounting is not used.
+ */
 void tty_port_init(struct tty_port *port)
 {
 	memset(port, 0, sizeof(*port));
@@ -82,9 +91,9 @@ EXPORT_SYMBOL(tty_port_init);
  * @index: index of the tty
  *
  * Provide the tty layer with a link from a tty (specified by @index) to a
- * tty_port (@port). Use this only if neither tty_port_register_device nor
- * tty_port_install is used in the driver. If used, this has to be called before
- * tty_register_driver.
+ * tty_port (@port). Use this only if neither tty_port_register_device() nor
+ * tty_port_install() is used in the driver. If used, this has to be called
+ * before tty_register_driver().
  */
 void tty_port_link_device(struct tty_port *port,
 		struct tty_driver *driver, unsigned index)
@@ -102,9 +111,9 @@ EXPORT_SYMBOL_GPL(tty_port_link_device);
  * @index: index of the tty
  * @device: parent if exists, otherwise NULL
  *
- * It is the same as tty_register_device except the provided @port is linked to
- * a concrete tty specified by @index. Use this or tty_port_install (or both).
- * Call tty_port_link_device as a last resort.
+ * It is the same as tty_register_device() except the provided @port is linked
+ * to a concrete tty specified by @index. Use this or tty_port_install() (or
+ * both). Call tty_port_link_device() as a last resort.
  */
 struct device *tty_port_register_device(struct tty_port *port,
 		struct tty_driver *driver, unsigned index,
@@ -123,9 +132,9 @@ EXPORT_SYMBOL_GPL(tty_port_register_device);
  * @drvdata: Driver data to be set to device.
  * @attr_grp: Attribute group to be set on device.
  *
- * It is the same as tty_register_device_attr except the provided @port is
- * linked to a concrete tty specified by @index. Use this or tty_port_install
- * (or both). Call tty_port_link_device as a last resort.
+ * It is the same as tty_register_device_attr() except the provided @port is
+ * linked to a concrete tty specified by @index. Use this or tty_port_install()
+ * (or both). Call tty_port_link_device() as a last resort.
  */
 struct device *tty_port_register_device_attr(struct tty_port *port,
 		struct tty_driver *driver, unsigned index,
@@ -240,9 +249,9 @@ EXPORT_SYMBOL(tty_port_free_xmit_buf);
  * tty_port_destroy -- destroy inited port
  * @port: tty port to be destroyed
  *
- * When a port was initialized using tty_port_init, one has to destroy the
- * port by this function. Either indirectly by using tty_port refcounting
- * (tty_port_put) or directly if refcounting is not used.
+ * When a port was initialized using tty_port_init(), one has to destroy the
+ * port by this function. Either indirectly by using &tty_port refcounting
+ * (tty_port_put()) or directly if refcounting is not used.
  */
 void tty_port_destroy(struct tty_port *port)
 {
@@ -267,6 +276,13 @@ static void tty_port_destructor(struct kref *kref)
 		kfree(port);
 }
 
+/**
+ * tty_port_put -- drop a reference to tty_port
+ * @port: port to drop a reference of (can be NULL)
+ *
+ * The final put will destroy and free up the @port using
+ * @port->ops->destruct() hook, or using kfree() if not provided.
+ */
 void tty_port_put(struct tty_port *port)
 {
 	if (port)
@@ -275,11 +291,11 @@ void tty_port_put(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_put);
 
 /**
- *	tty_port_tty_get	-	get a tty reference
- *	@port: tty port
+ * tty_port_tty_get	-	get a tty reference
+ * @port: tty port
  *
- *	Return a refcount protected tty instance or NULL if the port is not
- *	associated with a tty (eg due to close or hangup)
+ * Return a refcount protected tty instance or %NULL if the port is not
+ * associated with a tty (eg due to close or hangup).
  */
 struct tty_struct *tty_port_tty_get(struct tty_port *port)
 {
@@ -294,12 +310,12 @@ struct tty_struct *tty_port_tty_get(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_tty_get);
 
 /**
- *	tty_port_tty_set	-	set the tty of a port
- *	@port: tty port
- *	@tty: the tty
+ * tty_port_tty_set	-	set the tty of a port
+ * @port: tty port
+ * @tty: the tty
  *
- *	Associate the port and tty pair. Manages any internal refcounts.
- *	Pass NULL to deassociate a port
+ * Associate the port and tty pair. Manages any internal refcounts. Pass %NULL
+ * to deassociate a port.
  */
 void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
 {
@@ -312,6 +328,16 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
 }
 EXPORT_SYMBOL(tty_port_tty_set);
 
+/**
+ * tty_port_shutdown - internal helper to shutdown the device
+ * @port: tty port to be shut down
+ * @tty: the associated tty
+ *
+ * It is used by tty_port_hangup() and tty_port_close(). Its task is to
+ * shutdown the device if it was initialized (note consoles remain
+ * functioning). It lowers DTR/RTS (if @tty has HUPCL set) and invokes
+ * @port->ops->shutdown().
+ */
 static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty)
 {
 	mutex_lock(&port->mutex);
@@ -335,13 +361,13 @@ out:
 }
 
 /**
- *	tty_port_hangup		-	hangup helper
- *	@port: tty port
+ * tty_port_hangup		-	hangup helper
+ * @port: tty port
  *
- *	Perform port level tty hangup flag and count changes. Drop the tty
- *	reference.
+ * Perform port level tty hangup flag and count changes. Drop the tty
+ * reference.
  *
- *	Caller holds tty lock.
+ * Caller holds tty lock.
  */
 void tty_port_hangup(struct tty_port *port)
 {
@@ -365,9 +391,8 @@ EXPORT_SYMBOL(tty_port_hangup);
 
 /**
  * tty_port_tty_hangup - helper to hang up a tty
- *
  * @port: tty port
- * @check_clocal: hang only ttys with CLOCAL unset?
+ * @check_clocal: hang only ttys with %CLOCAL unset?
  */
 void tty_port_tty_hangup(struct tty_port *port, bool check_clocal)
 {
@@ -381,7 +406,6 @@ EXPORT_SYMBOL_GPL(tty_port_tty_hangup);
 
 /**
  * tty_port_tty_wakeup - helper to wake up a tty
- *
  * @port: tty port
  */
 void tty_port_tty_wakeup(struct tty_port *port)
@@ -391,12 +415,12 @@ void tty_port_tty_wakeup(struct tty_port *port)
 EXPORT_SYMBOL_GPL(tty_port_tty_wakeup);
 
 /**
- *	tty_port_carrier_raised	-	carrier raised check
- *	@port: tty port
+ * tty_port_carrier_raised	-	carrier raised check
+ * @port: tty port
  *
- *	Wrapper for the carrier detect logic. For the moment this is used
- *	to hide some internal details. This will eventually become entirely
- *	internal to the tty port.
+ * Wrapper for the carrier detect logic. For the moment this is used
+ * to hide some internal details. This will eventually become entirely
+ * internal to the tty port.
  */
 int tty_port_carrier_raised(struct tty_port *port)
 {
@@ -407,12 +431,12 @@ int tty_port_carrier_raised(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_carrier_raised);
 
 /**
- *	tty_port_raise_dtr_rts	-	Raise DTR/RTS
- *	@port: tty port
+ * tty_port_raise_dtr_rts	-	Raise DTR/RTS
+ * @port: tty port
  *
- *	Wrapper for the DTR/RTS raise logic. For the moment this is used
- *	to hide some internal details. This will eventually become entirely
- *	internal to the tty port.
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used to hide
+ * some internal details. This will eventually become entirely internal to the
+ * tty port.
  */
 void tty_port_raise_dtr_rts(struct tty_port *port)
 {
@@ -422,12 +446,12 @@ void tty_port_raise_dtr_rts(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_raise_dtr_rts);
 
 /**
- *	tty_port_lower_dtr_rts	-	Lower DTR/RTS
- *	@port: tty port
+ * tty_port_lower_dtr_rts	-	Lower DTR/RTS
+ * @port: tty port
  *
- *	Wrapper for the DTR/RTS raise logic. For the moment this is used
- *	to hide some internal details. This will eventually become entirely
- *	internal to the tty port.
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used to hide
+ * some internal details. This will eventually become entirely internal to the
+ * tty port.
  */
 void tty_port_lower_dtr_rts(struct tty_port *port)
 {
@@ -437,28 +461,29 @@ void tty_port_lower_dtr_rts(struct tty_port *port)
 EXPORT_SYMBOL(tty_port_lower_dtr_rts);
 
 /**
- *	tty_port_block_til_ready	-	Waiting logic for tty open
- *	@port: the tty port being opened
- *	@tty: the tty device being bound
- *	@filp: the file pointer of the opener or NULL
- *
- *	Implement the core POSIX/SuS tty behaviour when opening a tty device.
- *	Handles:
- *		- hangup (both before and during)
- *		- non blocking open
- *		- rts/dtr/dcd
- *		- signals
- *		- port flags and counts
- *
- *	The passed tty_port must implement the carrier_raised method if it can
- *	do carrier detect and the dtr_rts method if it supports software
- *	management of these lines. Note that the dtr/rts raise is done each
- *	iteration as a hangup may have previously dropped them while we wait.
- *
- *	Caller holds tty lock.
- *
- *      NB: May drop and reacquire tty lock when blocking, so tty and tty_port
- *      may have changed state (eg., may have been hung up).
+ * tty_port_block_til_ready	-	Waiting logic for tty open
+ * @port: the tty port being opened
+ * @tty: the tty device being bound
+ * @filp: the file pointer of the opener or %NULL
+ *
+ * Implement the core POSIX/SuS tty behaviour when opening a tty device.
+ * Handles:
+ *
+ *	- hangup (both before and during)
+ *	- non blocking open
+ *	- rts/dtr/dcd
+ *	- signals
+ *	- port flags and counts
+ *
+ * The passed @port must implement the @port->ops->carrier_raised method if it
+ * can do carrier detect and the @port->ops->dtr_rts method if it supports
+ * software management of these lines. Note that the dtr/rts raise is done each
+ * iteration as a hangup may have previously dropped them while we wait.
+ *
+ * Caller holds tty lock.
+ *
+ * Note: May drop and reacquire tty lock when blocking, so @tty and @port may
+ * have changed state (eg., may have been hung up).
  */
 int tty_port_block_til_ready(struct tty_port *port,
 				struct tty_struct *tty, struct file *filp)
@@ -560,7 +585,21 @@ static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty)
 	schedule_timeout_interruptible(timeout);
 }
 
-/* Caller holds tty lock. */
+/**
+ * tty_port_close_start - helper for tty->ops->close, part 1/2
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ * @filp: passed file pointer
+ *
+ * Decrements and checks open count. Flushes the port if this is the last
+ * close. That means, dropping the data from the outpu buffer on the device and
+ * waiting for sending logic to finish. The rest of close handling is performed
+ * in tty_port_close_end().
+ *
+ * Locking: Caller holds tty lock.
+ *
+ * Return: 1 if this is the last close, otherwise 0
+ */
 int tty_port_close_start(struct tty_port *port,
 				struct tty_struct *tty, struct file *filp)
 {
@@ -606,7 +645,17 @@ int tty_port_close_start(struct tty_port *port,
 }
 EXPORT_SYMBOL(tty_port_close_start);
 
-/* Caller holds tty lock */
+/**
+ * tty_port_close_end - helper for tty->ops->close, part 2/2
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ *
+ * This is a continuation of the first part: tty_port_close_start(). This
+ * should be called after turning off the device. It flushes the data from the
+ * line discipline and delays the close by @port->close_delay.
+ *
+ * Locking: Caller holds tty lock.
+ */
 void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
 {
 	unsigned long flags;
@@ -628,10 +677,18 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
 }
 EXPORT_SYMBOL(tty_port_close_end);
 
-/*
- * tty_port_close
+/**
+ * tty_port_close - generic tty->ops->close handler
+ * @port: tty_port of the device
+ * @tty: tty being closed
+ * @filp: passed file pointer
+ *
+ * It is a generic helper to be used in driver's @tty->ops->close. It wraps a
+ * sequence of tty_port_close_start(), tty_port_shutdown(), and
+ * tty_port_close_end(). The latter two are called only if this is the last
+ * close. See the respective functions for the details.
  *
- * Caller holds tty lock
+ * Locking: Caller holds tty lock
  */
 void tty_port_close(struct tty_port *port, struct tty_struct *tty,
 							struct file *filp)
@@ -652,9 +709,9 @@ EXPORT_SYMBOL(tty_port_close);
  * @driver: tty_driver for this device
  * @tty: tty to be installed
  *
- * It is the same as tty_standard_install except the provided @port is linked
- * to a concrete tty specified by @tty. Use this or tty_port_register_device
- * (or both). Call tty_port_link_device as a last resort.
+ * It is the same as tty_standard_install() except the provided @port is linked
+ * to a concrete tty specified by @tty. Use this or tty_port_register_device()
+ * (or both). Call tty_port_link_device() as a last resort.
  */
 int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 		struct tty_struct *tty)
@@ -664,13 +721,21 @@ int tty_port_install(struct tty_port *port, struct tty_driver *driver,
 }
 EXPORT_SYMBOL_GPL(tty_port_install);
 
-/*
- * tty_port_open
+/**
+ * tty_port_open - generic tty->ops->open handler
+ * @port: tty_port of the device
+ * @tty: tty to be opened
+ * @filp: passed file pointer
  *
- * Caller holds tty lock.
+ * It is a generic helper to be used in driver's @tty->ops->open. It activates
+ * the devices using @port->ops->activate if not active already. And waits for
+ * the device to be ready using tty_port_block_til_ready() (e.g.  raises
+ * DTR/CTS and waits for carrier).
+ *
+ * Locking: Caller holds tty lock.
  *
- * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so
- * tty and tty_port may have changed state (eg., may be hung up now)
+ * Note: may drop and reacquire tty lock (in tty_port_block_til_ready()) so
+ * @tty and @port may have changed state (eg., may be hung up now).
  */
 int tty_port_open(struct tty_port *port, struct tty_struct *tty,
 							struct file *filp)
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index c7fbbcdcc346..be8313cdbac3 100644
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -153,6 +153,7 @@ static int shift_state = 0;
 
 static unsigned int ledstate = -1U;			/* undefined */
 static unsigned char ledioctl;
+static bool vt_switch;
 
 /*
  * Notifier list for console keyboard events
@@ -324,13 +325,13 @@ int kbd_rate(struct kbd_repeat *rpt)
 static void put_queue(struct vc_data *vc, int ch)
 {
 	tty_insert_flip_char(&vc->port, ch, 0);
-	tty_schedule_flip(&vc->port);
+	tty_flip_buffer_push(&vc->port);
 }
 
 static void puts_queue(struct vc_data *vc, const char *cp)
 {
 	tty_insert_flip_string(&vc->port, cp, strlen(cp));
-	tty_schedule_flip(&vc->port);
+	tty_flip_buffer_push(&vc->port);
 }
 
 static void applkey(struct vc_data *vc, int key, char mode)
@@ -414,6 +415,12 @@ void vt_set_leds_compute_shiftstate(void)
 {
 	unsigned long flags;
 
+	/*
+	 * When VT is switched, the keyboard led needs to be set once.
+	 * Ensure that after the switch is completed, the state of the
+	 * keyboard LED is consistent with the state of the keyboard lock.
+	 */
+	vt_switch = true;
 	set_leds();
 
 	spin_lock_irqsave(&kbd_event_lock, flags);
@@ -584,7 +591,7 @@ static void fn_inc_console(struct vc_data *vc)
 static void fn_send_intr(struct vc_data *vc)
 {
 	tty_insert_flip_char(&vc->port, 0, TTY_BREAK);
-	tty_schedule_flip(&vc->port);
+	tty_flip_buffer_push(&vc->port);
 }
 
 static void fn_scroll_forw(struct vc_data *vc)
@@ -1255,6 +1262,11 @@ static void kbd_bh(struct tasklet_struct *unused)
 	leds |= (unsigned int)kbd->lockstate << 8;
 	spin_unlock_irqrestore(&led_lock, flags);
 
+	if (vt_switch) {
+		ledstate = ~leds;
+		vt_switch = false;
+	}
+
 	if (leds != ledstate) {
 		kbd_propagate_led_state(ledstate, leds);
 		ledstate = leds;
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 7359c3e80d63..f8c87c4d7399 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1833,7 +1833,7 @@ static void csi_m(struct vc_data *vc)
 static void respond_string(const char *p, size_t len, struct tty_port *port)
 {
 	tty_insert_flip_string(port, p, len);
-	tty_schedule_flip(port);
+	tty_flip_buffer_push(port);
 }
 
 static void cursor_report(struct vc_data *vc, struct tty_struct *tty)