Merge tag 'tty-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here are the big set of tty and serial driver changes for 5.18-rc1.

  Nothing major, some more good cleanups from Jiri and 2 new serial
  drivers. Highlights include:

   - termbits cleanups

   - export symbol cleanups and other core cleanups from Jiri Slaby

   - new sunplus and mvebu uart drivers (amazing that people are still
     creating new uarts...)

   - samsung serial driver cleanups

   - ldisc 29 is now "reserved" for experimental/development line
     disciplines

   - lots of other tiny fixes and cleanups to serial drivers and
     bindings

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (104 commits)
  vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE
  serial: 8250: fix XOFF/XON sending when DMA is used
  tty: serial: samsung: Add ARTPEC-8 support
  dt-bindings: serial: samsung: Add ARTPEC-8 UART
  serial: sc16is7xx: Clear RS485 bits in the shutdown
  tty: serial: samsung: simplify getting OF match data
  tty: serial: samsung: constify variables and pointers
  tty: serial: samsung: constify s3c24xx_serial_drv_data members
  tty: serial: samsung: constify UART name
  tty: serial: samsung: constify s3c24xx_serial_drv_data
  tty: serial: samsung: reduce number of casts
  tty: serial: samsung: embed s3c2410_uartcfg in parent structure
  tty: serial: samsung: embed s3c24xx_uart_info in parent structure
  serial: 8250_tegra: mark acpi_device_id as unused with !ACPI
  tty: serial: bcm63xx: use more precise Kconfig symbol
  serial: SERIAL_SUNPLUS should depend on ARCH_SUNPLUS
  tty: serial: jsm: fix two assignments in if conditions
  tty: serial: jsm: remove redundant assignments to variable linestatus
  serial: 8250_mtk: make two read-only arrays static const
  serial: samsung_tty: do not unlock port->lock for uart_write_wakeup()
  ...

13 files changed, 161 insertions, 105 deletions

diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 2350fb3bb5e4..93fe10c680fb 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -82,7 +82,7 @@ static ssize_t lpc_address_show(struct device *dev,
 	addr = (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRH) << 8) |
 		(aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRL));
 
-	return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr);
+	return sysfs_emit(buf, "0x%x\n", addr);
 }
 
 static int aspeed_vuart_set_lpc_address(struct aspeed_vuart *vuart, u32 addr)
@@ -124,7 +124,7 @@ static ssize_t sirq_show(struct device *dev,
 	reg &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
 	reg >>= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT;
 
-	return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg);
+	return sysfs_emit(buf, "%u\n", reg);
 }
 
 static int aspeed_vuart_set_sirq(struct aspeed_vuart *vuart, u32 sirq)
@@ -171,7 +171,7 @@ static ssize_t sirq_polarity_show(struct device *dev,
 	reg = aspeed_vuart_readb(vuart, ASPEED_VUART_GCRA);
 	reg &= ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY;
 
-	return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg ? 1 : 0);
+	return sysfs_emit(buf, "%u\n", reg ? 1 : 0);
 }
 
 static void aspeed_vuart_set_sirq_polarity(struct aspeed_vuart *vuart,
@@ -487,7 +487,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 	port.port.irq = irq_of_parse_and_map(np, 0);
 	port.port.handle_irq = aspeed_vuart_handle_irq;
 	port.port.iotype = UPIO_MEM;
-	port.port.type = PORT_16550A;
+	port.port.type = PORT_ASPEED_VUART;
 	port.port.uartclk = clk;
 	port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
 		| UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST;
diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
index fd95860cd661..2a1226a78a0c 100644
--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 
 #include "8250.h"
 
@@ -44,6 +45,10 @@ struct bcm2835aux_data {
 	u32 cntl;
 };
 
+struct bcm2835_aux_serial_driver_data {
+	resource_size_t offset;
+};
+
 static void bcm2835aux_rs485_start_tx(struct uart_8250_port *up)
 {
 	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
@@ -80,9 +85,12 @@ static void bcm2835aux_rs485_stop_tx(struct uart_8250_port *up)
 
 static int bcm2835aux_serial_probe(struct platform_device *pdev)
 {
+	const struct bcm2835_aux_serial_driver_data *bcm_data;
 	struct uart_8250_port up = { };
 	struct bcm2835aux_data *data;
+	resource_size_t offset = 0;
 	struct resource *res;
+	unsigned int uartclk;
 	int ret;
 
 	/* allocate the custom structure */
@@ -109,9 +117,7 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, data);
 
 	/* get the clock - this also enables the HW */
-	data->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(data->clk))
-		return dev_err_probe(&pdev->dev, PTR_ERR(data->clk), "could not get clk\n");
+	data->clk = devm_clk_get_optional(&pdev->dev, NULL);
 
 	/* get the interrupt */
 	ret = platform_get_irq(pdev, 0);
@@ -125,8 +131,24 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "memory resource not found");
 		return -EINVAL;
 	}
-	up.port.mapbase = res->start;
-	up.port.mapsize = resource_size(res);
+
+	bcm_data = device_get_match_data(&pdev->dev);
+
+	/* Some UEFI implementations (e.g. tianocore/edk2 for the Raspberry Pi)
+	 * describe the miniuart with a base address that encompasses the auxiliary
+	 * registers shared between the miniuart and spi.
+	 *
+	 * This is due to historical reasons, see discussion here :
+	 * https://edk2.groups.io/g/devel/topic/87501357#84349
+	 *
+	 * We need to add the offset between the miniuart and auxiliary
+	 * registers to get the real miniuart base address.
+	 */
+	if (bcm_data)
+		offset = bcm_data->offset;
+
+	up.port.mapbase = res->start + offset;
+	up.port.mapsize = resource_size(res) - offset;
 
 	/* Check for a fixed line number */
 	ret = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -141,12 +163,19 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	uartclk = clk_get_rate(data->clk);
+	if (!uartclk) {
+		ret = device_property_read_u32(&pdev->dev, "clock-frequency", &uartclk);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret, "could not get clk rate\n");
+	}
+
 	/* the HW-clock divider for bcm2835aux is 8,
 	 * but 8250 expects a divider of 16,
 	 * so we have to multiply the actual clock by 2
 	 * to get identical baudrates.
 	 */
-	up.port.uartclk = clk_get_rate(data->clk) * 2;
+	up.port.uartclk = uartclk * 2;
 
 	/* register the port */
 	ret = serial8250_register_8250_port(&up);
@@ -173,16 +202,27 @@ static int bcm2835aux_serial_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct bcm2835_aux_serial_driver_data bcm2835_acpi_data = {
+	.offset = 0x40,
+};
+
 static const struct of_device_id bcm2835aux_serial_match[] = {
 	{ .compatible = "brcm,bcm2835-aux-uart" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, bcm2835aux_serial_match);
 
+static const struct acpi_device_id bcm2835aux_serial_acpi_match[] = {
+	{ "BCM2836", (kernel_ulong_t)&bcm2835_acpi_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, bcm2835aux_serial_acpi_match);
+
 static struct platform_driver bcm2835aux_serial_driver = {
 	.driver = {
 		.name = "bcm2835-aux-uart",
 		.of_match_table = bcm2835aux_serial_match,
+		.acpi_match_table = bcm2835aux_serial_acpi_match,
 	},
 	.probe  = bcm2835aux_serial_probe,
 	.remove = bcm2835aux_serial_remove,
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 890fa7ddaa7f..b3c3f7e5851a 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -64,10 +64,19 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 	struct uart_8250_dma		*dma = p->dma;
 	struct circ_buf			*xmit = &p->port.state->xmit;
 	struct dma_async_tx_descriptor	*desc;
+	struct uart_port		*up = &p->port;
 	int ret;
 
-	if (dma->tx_running)
+	if (dma->tx_running) {
+		if (up->x_char) {
+			dmaengine_pause(dma->txchan);
+			uart_xchar_out(up, UART_TX);
+			dmaengine_resume(dma->txchan);
+		}
 		return 0;
+	} else if (up->x_char) {
+		uart_xchar_out(up, UART_TX);
+	}
 
 	if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
 		/* We have been called from __dma_tx_complete() */
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index c171ce6db691..e52585064565 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -86,7 +86,7 @@ static void serial8250_early_out(struct uart_port *port, int offset, int value)
 
 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
 
-static void serial_putc(struct uart_port *port, int c)
+static void serial_putc(struct uart_port *port, unsigned char c)
 {
 	unsigned int status;
 
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index d502240bbcf2..7292917ac878 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -623,7 +623,12 @@ exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
 
 	maxnr = pci_resource_len(pcidev, bar) >> (board->reg_shift + 3);
 
-	nr_ports = board->num_ports ? board->num_ports : pcidev->device & 0x0f;
+	if (pcidev->vendor == PCI_VENDOR_ID_ACCESSIO)
+		nr_ports = BIT(((pcidev->device & 0x38) >> 3) - 1);
+	else if (board->num_ports)
+		nr_ports = board->num_ports;
+	else
+		nr_ports = pcidev->device & 0x0f;
 
 	priv = devm_kzalloc(&pcidev->dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
 	if (!priv)
@@ -722,22 +727,6 @@ static int __maybe_unused exar_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(exar_pci_pm, exar_suspend, exar_resume);
 
-static const struct exar8250_board acces_com_2x = {
-	.num_ports	= 2,
-	.setup		= pci_xr17c154_setup,
-};
-
-static const struct exar8250_board acces_com_4x = {
-	.num_ports	= 4,
-	.setup		= pci_xr17c154_setup,
-};
-
-static const struct exar8250_board acces_com_8x = {
-	.num_ports	= 8,
-	.setup		= pci_xr17c154_setup,
-};
-
-
 static const struct exar8250_board pbn_fastcom335_2 = {
 	.num_ports	= 2,
 	.setup		= pci_fastcom335_setup,
@@ -822,13 +811,13 @@ static const struct exar8250_board pbn_exar_XR17V8358 = {
 	}
 
 static const struct pci_device_id exar_pci_tbl[] = {
-	EXAR_DEVICE(ACCESSIO, COM_2S, acces_com_2x),
-	EXAR_DEVICE(ACCESSIO, COM_4S, acces_com_4x),
-	EXAR_DEVICE(ACCESSIO, COM_8S, acces_com_8x),
-	EXAR_DEVICE(ACCESSIO, COM232_8, acces_com_8x),
-	EXAR_DEVICE(ACCESSIO, COM_2SM, acces_com_2x),
-	EXAR_DEVICE(ACCESSIO, COM_4SM, acces_com_4x),
-	EXAR_DEVICE(ACCESSIO, COM_8SM, acces_com_8x),
+	EXAR_DEVICE(ACCESSIO, COM_2S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_4S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_8S, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM232_8, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_2SM, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_4SM, pbn_exar_XR17C15x),
+	EXAR_DEVICE(ACCESSIO, COM_8SM, pbn_exar_XR17C15x),
 
 	CONNECT_DEVICE(XR17C152, UART_2_232, pbn_connect),
 	CONNECT_DEVICE(XR17C154, UART_4_232, pbn_connect),
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 65402d05eff9..cff91aa03f29 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -52,7 +52,7 @@ static void early_out(struct uart_port *port, int offset, uint8_t value)
 	writel(value, port->membase + (offset << 2));
 }
 
-static void ingenic_early_console_putc(struct uart_port *port, int c)
+static void ingenic_early_console_putc(struct uart_port *port, unsigned char c)
 {
 	uint8_t lsr;
 
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index d3bafec7619d..0f5af061e0b4 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -117,8 +117,7 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 {
 	struct dw_dma_slave *param = &lpss->dma_param;
 	struct pci_dev *pdev = to_pci_dev(port->dev);
-	unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
-	struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);
+	struct pci_dev *dma_dev;
 
 	switch (pdev->device) {
 	case PCI_DEVICE_ID_INTEL_BYT_UART1:
@@ -137,6 +136,8 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 		return -EINVAL;
 	}
 
+	dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+
 	param->dma_dev = &dma_dev->dev;
 	param->m_master = 0;
 	param->p_master = 1;
@@ -152,6 +153,14 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static void byt_serial_exit(struct lpss8250 *lpss)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+
+	/* Paired with pci_get_slot() in the byt_serial_setup() above */
+	put_device(param->dma_dev);
+}
+
 static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 {
 	struct uart_8250_dma *dma = &lpss->data.dma;
@@ -170,6 +179,13 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static void ehl_serial_exit(struct lpss8250 *lpss)
+{
+	struct uart_8250_port *up = serial8250_get_port(lpss->data.line);
+
+	up->dma = NULL;
+}
+
 #ifdef CONFIG_SERIAL_8250_DMA
 static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
 	.nr_channels = 2,
@@ -344,8 +360,7 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return 0;
 
 err_exit:
-	if (lpss->board->exit)
-		lpss->board->exit(lpss);
+	lpss->board->exit(lpss);
 	pci_free_irq_vectors(pdev);
 	return ret;
 }
@@ -356,8 +371,7 @@ static void lpss8250_remove(struct pci_dev *pdev)
 
 	serial8250_unregister_port(lpss->data.line);
 
-	if (lpss->board->exit)
-		lpss->board->exit(lpss);
+	lpss->board->exit(lpss);
 	pci_free_irq_vectors(pdev);
 }
 
@@ -365,12 +379,14 @@ static const struct lpss8250_board byt_board = {
 	.freq = 100000000,
 	.base_baud = 2764800,
 	.setup = byt_serial_setup,
+	.exit = byt_serial_exit,
 };
 
 static const struct lpss8250_board ehl_board = {
 	.freq = 200000000,
 	.base_baud = 12500000,
 	.setup = ehl_serial_setup,
+	.exit = ehl_serial_exit,
 };
 
 static const struct lpss8250_board qrk_board = {
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
index efa0515139f8..a2a03acb04ad 100644
--- a/drivers/tty/serial/8250/8250_mid.c
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -73,6 +73,11 @@ static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
 	return 0;
 }
 
+static void pnw_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
 static int tng_handle_irq(struct uart_port *p)
 {
 	struct mid8250 *mid = p->private_data;
@@ -124,6 +129,11 @@ static int tng_setup(struct mid8250 *mid, struct uart_port *p)
 	return 0;
 }
 
+static void tng_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
 static int dnv_handle_irq(struct uart_port *p)
 {
 	struct mid8250 *mid = p->private_data;
@@ -312,11 +322,9 @@ static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (!uart.port.membase)
 		return -ENOMEM;
 
-	if (mid->board->setup) {
-		ret = mid->board->setup(mid, &uart.port);
-		if (ret)
-			return ret;
-	}
+	ret = mid->board->setup(mid, &uart.port);
+	if (ret)
+		return ret;
 
 	ret = mid8250_dma_setup(mid, &uart);
 	if (ret)
@@ -330,9 +338,9 @@ static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	pci_set_drvdata(pdev, mid);
 	return 0;
+
 err:
-	if (mid->board->exit)
-		mid->board->exit(mid);
+	mid->board->exit(mid);
 	return ret;
 }
 
@@ -342,8 +350,7 @@ static void mid8250_remove(struct pci_dev *pdev)
 
 	serial8250_unregister_port(mid->line);
 
-	if (mid->board->exit)
-		mid->board->exit(mid);
+	mid->board->exit(mid);
 }
 
 static const struct mid8250_board pnw_board = {
@@ -351,6 +358,7 @@ static const struct mid8250_board pnw_board = {
 	.freq = 50000000,
 	.base_baud = 115200,
 	.setup = pnw_setup,
+	.exit = pnw_exit,
 };
 
 static const struct mid8250_board tng_board = {
@@ -358,6 +366,7 @@ static const struct mid8250_board tng_board = {
 	.freq = 38400000,
 	.base_baud = 1843200,
 	.setup = tng_setup,
+	.exit = tng_exit,
 };
 
 static const struct mid8250_board dnv_board = {
@@ -368,16 +377,14 @@ static const struct mid8250_board dnv_board = {
 	.exit = dnv_exit,
 };
 
-#define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
-
 static const struct pci_device_id pci_ids[] = {
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_CDF_UART, dnv_board),
-	MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
-	{ },
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART1, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART2, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, PNW_UART3, &pnw_board) },
+	{ PCI_DEVICE_DATA(INTEL, TNG_UART, &tng_board) },
+	{ PCI_DEVICE_DATA(INTEL, CDF_UART, &dnv_board) },
+	{ PCI_DEVICE_DATA(INTEL, DNV_UART, &dnv_board) },
+	{ }
 };
 MODULE_DEVICE_TABLE(pci, pci_ids);
 
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index fb65dc601b23..f4a0caa56f84 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -289,10 +289,10 @@ static void
 mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 			struct ktermios *old)
 {
-	unsigned short fraction_L_mapping[] = {
+	static const unsigned short fraction_L_mapping[] = {
 		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
 	};
-	unsigned short fraction_M_mapping[] = {
+	static const unsigned short fraction_M_mapping[] = {
 		0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
 	};
 	struct uart_8250_port *up = up_to_u8250p(port);
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 73e5f1dbd075..ac8bfa042391 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -357,21 +357,7 @@ static void omap_8250_set_termios(struct uart_port *port,
 	unsigned char cval = 0;
 	unsigned int baud;
 
-	switch (termios->c_cflag & CSIZE) {
-	case CS5:
-		cval = UART_LCR_WLEN5;
-		break;
-	case CS6:
-		cval = UART_LCR_WLEN6;
-		break;
-	case CS7:
-		cval = UART_LCR_WLEN7;
-		break;
-	default:
-	case CS8:
-		cval = UART_LCR_WLEN8;
-		break;
-	}
+	cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
 
 	if (termios->c_cflag & CSTOPB)
 		cval |= UART_LCR_STOP;
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3b12bfc1ed67..318af6f13605 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -307,6 +307,14 @@ static const struct serial8250_config uart_config[] = {
 		.rxtrig_bytes	= {1, 32, 64, 112},
 		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
 	},
+	[PORT_ASPEED_VUART] = {
+		.name		= "ASPEED VUART",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
 };
 
 /* Uart divisor latch read */
@@ -1615,6 +1623,18 @@ static inline void start_tx_rs485(struct uart_port *port)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	struct uart_8250_em485 *em485 = up->em485;
 
+	/*
+	 * While serial8250_em485_handle_stop_tx() is a noop if
+	 * em485->active_timer != &em485->stop_tx_timer, it might happen that
+	 * the timer is still armed and triggers only after the current bunch of
+	 * chars is send and em485->active_timer == &em485->stop_tx_timer again.
+	 * So cancel the timer. There is still a theoretical race condition if
+	 * the timer is already running and only comes around to check for
+	 * em485->active_timer when &em485->stop_tx_timer is armed again.
+	 */
+	if (em485->active_timer == &em485->stop_tx_timer)
+		hrtimer_try_to_cancel(&em485->stop_tx_timer);
+
 	em485->active_timer = NULL;
 
 	if (em485->tx_stopped) {
@@ -1657,6 +1677,9 @@ static void serial8250_start_tx(struct uart_port *port)
 
 	serial8250_rpm_get_tx(up);
 
+	if (!port->x_char && uart_circ_empty(&port->state->xmit))
+		return;
+
 	if (em485 &&
 	    em485->active_timer == &em485->start_tx_timer)
 		return;
@@ -1799,9 +1822,7 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 	int count;
 
 	if (port->x_char) {
-		serial_out(up, UART_TX, port->x_char);
-		port->icount.tx++;
-		port->x_char = 0;
+		uart_xchar_out(port, UART_TX);
 		return;
 	}
 	if (uart_tx_stopped(port)) {
@@ -2582,21 +2603,7 @@ static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
 {
 	unsigned char cval;
 
-	switch (c_cflag & CSIZE) {
-	case CS5:
-		cval = UART_LCR_WLEN5;
-		break;
-	case CS6:
-		cval = UART_LCR_WLEN6;
-		break;
-	case CS7:
-		cval = UART_LCR_WLEN7;
-		break;
-	default:
-	case CS8:
-		cval = UART_LCR_WLEN8;
-		break;
-	}
+	cval = UART_LCR_WLEN(tty_get_char_size(c_cflag));
 
 	if (c_cflag & CSTOPB)
 		cval |= UART_LCR_STOP;
@@ -3296,7 +3303,7 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults);
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
-static void serial8250_console_putchar(struct uart_port *port, int ch)
+static void serial8250_console_putchar(struct uart_port *port, unsigned char ch)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
diff --git a/drivers/tty/serial/8250/8250_tegra.c b/drivers/tty/serial/8250/8250_tegra.c
index e13ae18b0713..e7cddeec9d8e 100644
--- a/drivers/tty/serial/8250/8250_tegra.c
+++ b/drivers/tty/serial/8250/8250_tegra.c
@@ -175,7 +175,7 @@ static const struct of_device_id tegra_uart_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
 
-static const struct acpi_device_id tegra_uart_acpi_match[] = {
+static const struct acpi_device_id tegra_uart_acpi_match[] __maybe_unused = {
 	{ "NVDA0100", 0 },
 	{ },
 };
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 9d415a38cc71..cd93ea6eed65 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -479,11 +479,12 @@ config SERIAL_8250_LPSS
 	select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
 	select RATIONAL
 	help
-	  Selecting this option will enable handling of the extra features
-	  present on the UART found on various Intel platforms such as:
+	  Selecting this option will enable handling of the UART found on
+	  various Intel platforms such as:
 	    - Intel Baytrail SoC
 	    - Intel Braswell SoC
 	    - Intel Quark X1000 SoC
+	  that are not covered by the more generic SERIAL_8250_PCI option.
 
 config SERIAL_8250_MID
 	tristate "Support for serial ports on Intel MID platforms"
@@ -494,17 +495,18 @@ config SERIAL_8250_MID
 	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
 	select RATIONAL
 	help
-	  Selecting this option will enable handling of the extra features
-	  present on the UART found on Intel Medfield SOC and various other
-	  Intel platforms.
+	  Selecting this option will enable handling of the UART found on
+	  Intel Medfield SOC and various other Intel platforms that is not
+	  covered by the more generic SERIAL_8250_PCI option.
 
 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.
+	  Selecting this option will enable handling of the Pericom and Acces
+	  I/O UARTs that are not covered by the more generic SERIAL_8250_PCI
+	  option.
 
 config SERIAL_8250_PXA
 	tristate "PXA serial port support"