[PATCH] ASoC: dmic: Allow GPIO operations to sleep

[Tzung-Bi Shih]

On Wed, Apr 22, 2020 at 4:37 PM Mark Brown <broonie at kernel.org> wrote:
>
> If there is a power GPIO provided we control it from DAPM context so there
> is no problem with a sleeping GPIO, use the _cansleep() version of the API
> to allow this.

Compared gpiod_set_value_cansleep() vs. gpiod_set_value().

gpiod_set_value_cansleep()
+        might_sleep_if(extra_checks);

gpiod_set_value()
+        /* Should be using gpiod_set_value_cansleep() */
+        WARN_ON(desc->gdev->chip->can_sleep);

And the extra_checks is:
#ifdef  DEBUG
#define extra_checks    1
#else
#define extra_checks    0
#endif

Looks like it only changes behavior when DEBUG.

Wondering about:
- Did you get any warning message to inspire you to use _cansleep() version?
- Does that imply in any _can sleep_ context, it is more encouraged to
call _cansleep() version?  (e.g.
https://elixir.bootlin.com/linux/v5.7-rc2/source/sound/soc/codecs/max98357a.c#L41)