This is a note to let you know that I've just added the patch titled
serial: core: introduce uart_port_tx_flags()
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-core-introduce-uart_port_tx_flags.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3ee07964d407411fd578a3bc998de44fd64d266a Mon Sep 17 00:00:00 2001
From: "Jiri Slaby (SUSE)" <jirislaby@xxxxxxxxxx>
Date: Thu, 1 Feb 2024 11:55:56 +0100
Subject: serial: core: introduce uart_port_tx_flags()
From: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
commit 3ee07964d407411fd578a3bc998de44fd64d266a upstream.
And an enum with a flag: UART_TX_NOSTOP. To NOT call
__port->ops->stop_tx() when the circular buffer is empty. mxs-uart needs
this (see the next patch).
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Tested-by: Emil Kronborg <emil.kronborg@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240201105557.28043-1-jirislaby@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/serial_core.h | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
--- 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
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
*/
#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
* 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.
*/
Patches currently in stable-queue which might be from jirislaby@xxxxxxxxxx are
queue-6.7/mm-huge_memory-don-t-force-huge-page-alignment-on-32-bit.patch
queue-6.7/serial-mxs-auart-fix-tx.patch
queue-6.7/serial-core-introduce-uart_port_tx_flags.patch
