Hello Geert,
On Mon, Mar 16, 2020 at 04:42:31PM +0100, Geert Uytterhoeven wrote:
> On Mon, Mar 16, 2020 at 4:40 PM Uwe Kleine-König
> <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> > On Mon, Mar 16, 2020 at 11:32:14AM +0100, Geert Uytterhoeven wrote:
> > > Runtime PM should be enabled before calling pwmchip_add(), as PWM users
> > > can appear immediately after the PWM chip has been added.
> > > Likewise, Runtime PM should be disabled after the removal of the PWM
> > > chip.
> > >
> > > Fixes: ed6c1476bf7f16d5 ("pwm: Add support for R-Car PWM Timer")
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > > ---
> > > drivers/pwm/pwm-rcar.c | 10 +++++++---
> > > 1 file changed, 7 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
> > > index 2685577b6dd45be7..7ab9eb6616d950cb 100644
> > > --- a/drivers/pwm/pwm-rcar.c
> > > +++ b/drivers/pwm/pwm-rcar.c
> > > @@ -229,24 +229,28 @@ static int rcar_pwm_probe(struct platform_device *pdev)
> > > rcar_pwm->chip.base = -1;
> > > rcar_pwm->chip.npwm = 1;
> > >
> > > + pm_runtime_enable(&pdev->dev);
> > > +
> > > ret = pwmchip_add(&rcar_pwm->chip);
> > > if (ret < 0) {
> > > dev_err(&pdev->dev, "failed to register PWM chip: %d\n", ret);
> > > + pm_runtime_disable(&pdev->dev);
> > > return ret;
> > > }
> > >
> > > - pm_runtime_enable(&pdev->dev);
> > > -
> >
> > Wouldn't it be wiser to do the pm_runtime_enable in .request, or even in
> > .apply when enabled=true?
>
> Wouldn't that mean that the device cannot be powered down until the first
> time a PWM is used?
Ah, it seems I got the semantic of pm_runtime_enable() wrong. I confused
it with pm_runtime_get(). Now with that corrected your fix is obviously
right:
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Thanks
Uwe
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