From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
When 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in
driver-specific way") got backported to 5.10.y, there known as
26a2b9c468de, some hunks were accidentally left out.
In serial_core.c, it is possible that the omission in
uart_suspend_port() is harmless, but the backport did have the
corresponding hunk in uart_resume_port(), it runs counter to the
original commit's intention of
Skip any invocation of ->set_mctrl() if RS485 is enabled.
and it's certainly better to be aligned with upstream.
Link: https://lkml.kernel.org/r/20221222114414.1886632-1-linux@xxxxxxxxxxxxxxxxxx
Fixes: 26a2b9c468de ("serial: Deassert Transmit Enable on probe in driver-specific way")
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
[the fsl_lpuart part of the 5.15 patch is not required on 5.10,
because the code before 26a2b9c468de was incorrectly not calling
uart_remove_one_port on failed_get_rs485]
Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx>
---
The part in v2 of the patch still makes sense, so here's just that for
5.10.
(I've kept Rasmus as author for the 5.10 version as well, thanks again!)
drivers/tty/serial/serial_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 605f928f0636..40fff38588d4 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2254,7 +2254,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
spin_lock_irq(&uport->lock);
ops->stop_tx(uport);
- ops->set_mctrl(uport, 0);
+ if (!(uport->rs485.flags & SER_RS485_ENABLED))
+ ops->set_mctrl(uport, 0);
ops->stop_rx(uport);
spin_unlock_irq(&uport->lock);
--
2.35.1
