Re: [PATCH] serial: core: stop passing NULL in uart_resume_port

From: Andy Shevchenko
Date: Wed Jul 25 2018 - 18:01:49 EST


On Wed, Jul 25, 2018 at 1:04 PM, Chen Hu <hu1.chen@xxxxxxxxx> wrote:
> We found the baud rate is changed after S3 on some Intel Broxton
> platforms. The baud rate should be restored during resume. However, some
> set_termios() callback such as dw8250_set_termios() for DesignWare 8250
> will skip setting if old termios is NULL. We address this issue via
> passing a dummy.

Why does it need to be "fixed" here then?

>
> Signed-off-by: Chen Hu <hu1.chen@xxxxxxxxx>
> ---
> 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 f02965936f2e..8b815f1539e8 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2217,6 +2217,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
> struct device *tty_dev;
> struct uart_match match = {uport, drv};
> struct ktermios termios;
> + static struct ktermios dummy;
>
> mutex_lock(&port->mutex);
>
> @@ -2277,7 +2278,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
> pm_runtime_put_autosuspend(uport->dev);
> if (ret == 0) {
> if (tty)
> - uart_change_speed(tty, state, NULL);
> + uart_change_speed(tty, state, &dummy);
> pm_runtime_get_sync(uport->dev);
> spin_lock_irq(&uport->lock);
> ops->set_mctrl(uport, uport->mctrl);
> --
> 2.13.0
>



--
With Best Regards,
Andy Shevchenko