Re: [PATCH v4 1/4] pwm: dwc: Fix PM regression

From: Raag Jadav
Date: Mon Feb 19 2024 - 04:06:34 EST


On Mon, Feb 19, 2024 at 08:22:15AM +0100, Uwe Kleine-König wrote:
> Hello Raag,
>
> On Mon, Feb 19, 2024 at 09:08:32AM +0530, Raag Jadav wrote:
> > While preparing dwc driver for devm_pwmchip_alloc() usage, commit
> > df41cd8bbcad ("pwm: dwc: Prepare removing pwm_chip from driver data")
> > modified ->suspend() handle to use the pwm_chip as driver_data for
> > accessing struct dwc_pwm, but didn't modify ->resume() handle with
> > relevant changes. This results into illegal memory access during
> > device wakeup and causes a PM regression.
> >
> > Fix this by correctly accessing struct dwc_pwm in ->resume() handle.
> >
> > Fixes: df41cd8bbcad ("pwm: dwc: Prepare removing pwm_chip from driver data")
> > Signed-off-by: Raag Jadav <raag.jadav@xxxxxxxxx>
> > ---
> > drivers/pwm/pwm-dwc.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
> > index 8ca1c20a6aaf..c0e586688e57 100644
> > --- a/drivers/pwm/pwm-dwc.c
> > +++ b/drivers/pwm/pwm-dwc.c
> > @@ -95,7 +95,8 @@ static int dwc_pwm_suspend(struct device *dev)
> >
> > static int dwc_pwm_resume(struct device *dev)
> > {
> > - struct dwc_pwm *dwc = dev_get_drvdata(dev);
> > + struct pwm_chip *chip = dev_get_drvdata(dev);
> > + struct dwc_pwm *dwc = to_dwc_pwm(chip);
> > int i;
> >
> > for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
>
> If you're ok I'd squash this into df41cd8bbcad adding
>
> Thanks to Raag Jadav for providing a hunk of this patch that Uwe
> missed during creation of this patch.
>
> to the commit log.

Works for me.

Raag