On Wed, Sep 24, 2025 at 11:15:49AM +0800, Sherry Sun wrote:
> Currently, the i.MX UART driver enables wake-related registers for all
> UART devices by default. However, this is unnecessary for devices that
> are not configured as wakeup sources. To address this, add a
> device_may_wakeup() check before configuring the UART wake-related
> registers.
>
> Fixes: db1a9b55004c ("tty: serial: imx: Allow UART to be a source for wakeup")
> Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
> ---
Reviewed-by: Frank Li <Frank.Li@nxp.com>
> drivers/tty/serial/imx.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 500dfc009d03..87d841c0b22f 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -2697,8 +2697,23 @@ static void imx_uart_save_context(struct imx_port *sport)
> /* called with irq off */
> static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
> {
> + struct tty_port *port = &sport->port.state->port;
> + struct tty_struct *tty;
> + struct device *tty_dev;
> + bool may_wake = false;
> u32 ucr3;
>
> + tty = tty_port_tty_get(port);
> + if (tty) {
> + tty_dev = tty->dev;
> + may_wake = tty_dev && device_may_wakeup(tty_dev);
> + tty_kref_put(tty);
> + }
> +
> + /* only configure the wake register when device set as wakeup source */
> + if (!may_wake)
> + return;
> +
> uart_port_lock_irq(&sport->port);
>
> ucr3 = imx_uart_readl(sport, UCR3);
> --
> 2.34.1
>