Hi Uwe,
On Mon, Mar 16, 2020 at 5:01 PM Uwe Kleine-König
<u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
> On Mon, Mar 16, 2020 at 11:32:15AM +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 always be disabled after the removal of the
> > PWM chip, even if the latter failed.
> >
> > Fixes: 99b82abb0a35b073 ("pwm: Add Renesas TPU PWM driver")
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > ---
> > drivers/pwm/pwm-renesas-tpu.c | 9 ++++-----
> > 1 file changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c
> > index 4a855a21b782dea3..8032acc84161a9dd 100644
> > --- a/drivers/pwm/pwm-renesas-tpu.c
> > +++ b/drivers/pwm/pwm-renesas-tpu.c
> > @@ -415,16 +415,17 @@ static int tpu_probe(struct platform_device *pdev)
> > tpu->chip.base = -1;
> > tpu->chip.npwm = TPU_CHANNEL_MAX;
> >
> > + pm_runtime_enable(&pdev->dev);
> > +
> > ret = pwmchip_add(&tpu->chip);
> > if (ret < 0) {
> > dev_err(&pdev->dev, "failed to register PWM chip\n");
> > + pm_runtime_disable(&pdev->dev);
> > return ret;
> > }
> >
> > dev_info(&pdev->dev, "TPU PWM %d registered\n", tpu->pdev->id);
> >
> > - pm_runtime_enable(&pdev->dev);
> > -
> > return 0;
> > }
> >
> > @@ -434,12 +435,10 @@ static int tpu_remove(struct platform_device *pdev)
> > int ret;
> >
> > ret = pwmchip_remove(&tpu->chip);
> > - if (ret)
> > - return ret;
> >
> > pm_runtime_disable(&pdev->dev);
> >
> > - return 0;
> > + return ret;
> > }
>
> Maybe I was a bit quick with my reply to the previous patch. I wonder if
> it is right to call pm_runtime_disable if pwmchip_remove failed?
While the pwmchip may still exist, the hardware is unmapped and no
longer accessible.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
