Re: [PATCH] ALSA: pcm: Release paused streams before suspend if resume is not supported

["Péter Ujfalusi" <peter.ujfalusi@linux.intel.com>]

On 02/04/2025 14:21, Takashi Iwai wrote:
>>> On the second thought, yet another variant would be to introduce only
>>> one new trigger, SNDRV_PCM_TRIGGER_PAUSE_RESET, for resetting the
>>> PAUSED state as a step before stopping the stream.  This can be
>>> applied to all cases for snd_pcm_drop() and snd_pcm_suspend(), too.
>>> If the driver doesn't support this mode, the PCM core may fall back to
>>> SNDRV_PCM_TRIGGER_PAUSE_RELEASE.
>>
>> This looks identical to my proposed
>> SNDRV_PCM_TRIGGER_PAUSE_RELEASE_AND_STOP which is more
>> explanatory. It's not clear what PAUSE_RESET should do (probably the
>> stream should be kept inactive).
> 
> There is a slight difference.  My proposal, *_TRIGGER_PAUSE_RESET,
> doesn't have to stop the stream by itself, but it's only a preparation
> for stopping.  That is, a proper TRIGGER_STOP always follows after
> TRIGGER_PAUSE_RESET.

But what state that we move after we reset the PAUSE? is it RUNNING
(iow, equals to PAUSE_RELEASE) or something else?

In case of suspend while the state is paused we will:
TRIGGER_PAUSE_RESET followed by STOP or SUSPEND?

Most drivers are doing the same thing for STOP and SUSPEND trigger,
however it is possible to do extra steps for SUSPEND to make sure that
the whole system is in a lowest power state.

-- 
Péter