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authorLinus Torvalds <torvalds@linux-foundation.org>2024-02-17 08:46:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-02-17 08:46:57 -0800
commit4b2981b2270d7b9be6c15f80d5c4b838ad93ceef (patch)
tree749cadaeac59ffe091ed66dcff2a326a19f4db65
parenta3a7d1627429545cddcc60314f1596912138daf1 (diff)
parent7be50f2e8f20fc2299069b28dea59a28e3abe20a (diff)
Merge tag 'tty-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial fixes from Greg KH: "Here are three small tty and serial driver fixes for 6.8-rc5: - revert a 8250_pci1xxxx off-by-one change that was incorrect - two changes to fix the transmit path of the mxs-auart driver, fixing a regression in the 6.2 release All of these have been in linux-next for over a week with no reported issues" * tag 'tty-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: mxs-auart: fix tx serial: core: introduce uart_port_tx_flags() serial: 8250_pci1xxxx: partially revert off by one patch
-rw-r--r--drivers/tty/serial/8250/8250_pci1xxxx.c2
-rw-r--r--drivers/tty/serial/mxs-auart.c5
-rw-r--r--include/linux/serial_core.h32
3 files changed, 32 insertions, 7 deletions
diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
index cd258922bd78..2dda737b1660 100644
--- a/drivers/tty/serial/8250/8250_pci1xxxx.c
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
@@ -302,7 +302,7 @@ static void pci1xxxx_process_read_data(struct uart_port *port,
* to read, the data is received one byte at a time.
*/
while (valid_burst_count--) {
- if (*buff_index >= (RX_BUF_SIZE - UART_BURST_SIZE))
+ if (*buff_index > (RX_BUF_SIZE - UART_BURST_SIZE))
break;
burst_buf = (u32 *)&rx_buff[*buff_index];
*burst_buf = readl(port->membase + UART_RX_BURST_FIFO);
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 3ec725555bcc..4749331fe618 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -605,13 +605,16 @@ static void mxs_auart_tx_chars(struct mxs_auart_port *s)
return;
}
- pending = uart_port_tx(&s->port, ch,
+ pending = uart_port_tx_flags(&s->port, ch, UART_TX_NOSTOP,
!(mxs_read(s, REG_STAT) & AUART_STAT_TXFF),
mxs_write(ch, s, REG_DATA));
if (pending)
mxs_set(AUART_INTR_TXIEN, s, REG_INTR);
else
mxs_clr(AUART_INTR_TXIEN, s, REG_INTR);
+
+ if (uart_tx_stopped(&s->port))
+ mxs_auart_stop_tx(&s->port);
}
static void mxs_auart_rx_char(struct mxs_auart_port *s)
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 536b2581d3e2..55b1f3ba48ac 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -748,8 +748,17 @@ struct uart_driver {
void uart_write_wakeup(struct uart_port *port);
-#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test, \
- for_post) \
+/**
+ * enum UART_TX_FLAGS -- flags for uart_port_tx_flags()
+ *
+ * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer
+ */
+enum UART_TX_FLAGS {
+ UART_TX_NOSTOP = BIT(0),
+};
+
+#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done, \
+ for_test, for_post) \
({ \
struct uart_port *__port = (uport); \
struct circ_buf *xmit = &__port->state->xmit; \
@@ -777,7 +786,7 @@ void uart_write_wakeup(struct uart_port *port);
if (pending < WAKEUP_CHARS) { \
uart_write_wakeup(__port); \
\
- if (pending == 0) \
+ if (!((flags) & UART_TX_NOSTOP) && pending == 0) \
__port->ops->stop_tx(__port); \
} \
\
@@ -812,7 +821,7 @@ void uart_write_wakeup(struct uart_port *port);
*/
#define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \
unsigned int __count = (count); \
- __uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count, \
+ __uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count, \
__count--); \
})
@@ -826,8 +835,21 @@ void uart_write_wakeup(struct uart_port *port);
* See uart_port_tx_limited() for more details.
*/
#define uart_port_tx(port, ch, tx_ready, put_char) \
- __uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({}))
+ __uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))
+
+/**
+ * uart_port_tx_flags -- transmit helper for uart_port with flags
+ * @port: uart port
+ * @ch: variable to store a character to be written to the HW
+ * @flags: %UART_TX_NOSTOP or similar
+ * @tx_ready: can HW accept more data function
+ * @put_char: function to write a character
+ *
+ * See uart_port_tx_limited() for more details.
+ */
+#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char) \
+ __uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))
/*
* Baud rate helpers.
*/