Hi Shimoda-san,
On Thu, May 30, 2019 at 12:21 PM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> According to the Documentation/pwm.txt, all PWM consumers should have
> power management. Since this sysfs interface is one of consumers so that
> this patch adds suspend/resume support.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Thanks for your patch!
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> --- a/drivers/pwm/sysfs.c
> +++ b/drivers/pwm/sysfs.c
> @@ -372,10 +373,109 @@ static struct attribute *pwm_chip_attrs[] = {
> };
> ATTRIBUTE_GROUPS(pwm_chip);
>
You may want to add a comment "takes export->lock on success" here...
> +static struct pwm_export *pwm_class_get_state(struct device *parent,
> + struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + struct device *child;
> + struct pwm_export *export;
> +
> + if (!test_bit(PWMF_EXPORTED, &pwm->flags))
> + return NULL;
> +
> + child = device_find_child(parent, pwm, pwm_unexport_match);
> + if (!child)
> + return NULL;
> +
> + export = child_to_pwm_export(child);
> + put_device(child); /* for device_find_child() */
> +
> + mutex_lock(&export->lock);
> + pwm_get_state(pwm, state);
> +
> + return export;
> +}
> +
> +static int pwm_class_apply_state(struct pwm_export *export,
> + struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + int ret = pwm_apply_state(pwm, state);
> +
... and "release lock taken in pwm_class_get_state()" here.
> + mutex_unlock(&export->lock);
> +
> + return ret;
> +}
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
