RE: [PATCH tty v1 2/8] serial: core: lock port for stop_rx() in uart_suspend_port()

Vijaya Krishna Nivarthi (Temp) (QUIC)
2023-05-25T17:47:37Z

++Doug

Hi,

> -----Original Message-----
> From: John Ogness <john.ogness@linutronix.de>
> Sent: Thursday, May 25, 2023 3:02 PM
> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Petr Mladek <pmladek@suse.com>; Thomas Gleixner
> <tglx@linutronix.de>; linux-kernel@vger.kernel.org; Jiri Slaby
> <jirislaby@kernel.org>; Vijaya Krishna Nivarthi (Temp) (QUIC)
> <quic_vnivarth@quicinc.com>; linux-serial@vger.kernel.org
> Subject: [PATCH tty v1 2/8] serial: core: lock port for stop_rx() in
> uart_suspend_port()
>
> WARNING: This email originated from outside of Qualcomm. Please be wary
> of any links or attachments, and do not enable macros.
>
> 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>
> ---
> 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 4b98d13555c0..37ad53616372 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);
> + }

Looks correct to me.
Thank you for the fix.

-Vijay/

> goto unlock;
> }
>
> --
> 2.30.2