[PATCH 6.4 595/800] serial: core: lock port for stop_rx() in uart_suspend_port()

Greg Kroah-Hartman
2023-07-16T20:22:04Z

From: John Ogness <john.ogness@linutronix.de>

[ Upstream commit abcb0cf1f5b2d99b1d117a4dbce334120e358d6d ]

The uarts_ops stop_rx() callback expects that the port->lock is
taken and interrupts are disabled.

Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230525093159.223817-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/serial_core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 54e82f476a2cc..a664778492c46 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2333,8 +2333,11 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
* able to Re-start_rx later.
*/
if (!console_suspend_enabled && uart_console(uport)) {
- if (uport->ops->start_rx)
+ if (uport->ops->start_rx) {
+ spin_lock_irq(&uport->lock);
uport->ops->stop_rx(uport);
+ spin_unlock_irq(&uport->lock);
+ }
goto unlock;
}

--
2.39.2