On 2021-11-05 12:36 PM, Takashi Iwai wrote:
On Fri, 05 Nov 2021 12:30:48 +0100,
Cezary Rojewski wrote:
On 2021-11-05 10:09 AM, Takashi Iwai wrote:
The recent fix for DAPM to correct the kctl change notification by the
commit 5af82c81b2c4 ("ASoC: DAPM: Fix missing kctl change
notifications") caused other regressions since it changed the behavior
of snd_soc_dapm_set_pin() that is called from several API functions.
Formerly it returned always 0 for success, but now it returns 0 or 1.
This patch addresses it, restoring the old behavior of
snd_soc_dapm_set_pin() while keeping the fix in
snd_soc_dapm_put_pin_switch().
Fixes: 5af82c81b2c4 ("ASoC: DAPM: Fix missing kctl change notifications")
Reported-by: Yu-Hsuan Hsu <yuhsuan@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Hello,
From my research I've found very few places which actually check the
returned value of functions mentioned by you. And thus we could use
this opportunity to adjust the kcontrol-put behavior according to
documentation for all users without adding any additional functions
which are part of this patch.
Board:
sound/soc/intel/boards/kbl_da7219_max98927.c
seems to be the offending user. We could update its code instead,
leaving ASoC unchanged. What do you think?
Well, if we're going to that direction, we have to update the
documentation and properly mention about the positive return value.
So the changes in ASoC core would be needed nevertheless.
I find it good to keep the old existing behavior; those API functions
are only for enabling/disabling, so returning 0 or a negative error is
more natural than tri-state, less complex for callers.
Hmm, indeed ASoC API doc would need an update, ASoC DAPM api != kcontrol
api after all.
My impression of original patch was the desire to align the behaviour of
snd_soc_dapm_enable/disable_pin() and similar functions with
kcontrol-put equivalents - in terms of the returned value. Perhaps
that's not the case.
While it's preferred the keep the existing behaviour, if we were to
align DAPM functions with kcontrol-put ones, fact that vast majority of
users ignore the returned value, helps us out.
Regards,
Czarek
