RE: [PATCH V3 1/2] tty: serial: imx: Only configure the wake register when device is set as wakeup source

[Sherry Sun]

> -----Original Message-----
> From: Jiri Slaby <jirislaby@xxxxxxxxxx>
> Sent: Monday, September 29, 2025 1:54 PM
> To: Sherry Sun <sherry.sun@xxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx;
> shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx;
> festevam@xxxxxxxxx; Shenwei Wang <shenwei.wang@xxxxxxx>; Peng Fan
> <peng.fan@xxxxxxx>; Frank Li <frank.li@xxxxxxx>
> Cc: linux-serial@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> imx@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH V3 1/2] tty: serial: imx: Only configure the wake register
> when device is set as wakeup source
> 
> On 25. 09. 25, 11:11, 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@xxxxxxx>
> > Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> >   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) {
> 
> Use scoped_guard(tty_port_tty, port) instead.

Sure, will add this in next version.

Best Regards
Sherry