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

[Jaroslav Kysela <perex@perex.cz>]

On 01. 04. 25 16:49, Takashi Iwai wrote:
> On Tue, 01 Apr 2025 15:36:52 +0200,
> Peter Ujfalusi wrote:
>>
>> Streams moved to SUSPENDED state from PAUSED without trigger. If a stream
>> does not support RESUME then on system resume the RESUME trigger is not
>> sent, the stream's state and suspended_state remains untouched.
>> When the user space releases the pause then the core will reject this
>> because the state of the stream is _not_ PAUSED, it is still SUSPENDED.
>>
>>  From this point user space will do the normal (hw_params) prepare and
>> START, PAUSE_RELEASE trigger will not be sent by the core after the
>> system has resumed.

Why you expect to see PAUSE_RELEASE trigger before SUSPEND trigger when resume 
is not supported ? I think that the driver has complete information:

PAUSE -> SUSPEND [-> no RESUME]

The driver should stay in the suspend state until a new stream 
re-initialization is invoked.

It looks like that other logic should be moved to the end driver (if some 
parts must be reinitialized in the suspend phase when the resume is not 
supported). I don't think that this is job for PCM core nor SoC PCM core routines.

The SUSPEND trigger is always invoked, isn't?

>> To fix this issue, release the paused stream before handling the suspend
>> if the resume is not supported.
>> This will ensure that the stream is properly suspended for suspend entry.
>> On resume no attempt will be taken to resume the suspended stream as the
>> resume is not supported, userspace will eventually going restart the audio.
>>
>> Link: https://github.com/thesofproject/linux/issues/5035
>> Link: https://github.com/thesofproject/linux/issues/5341
>> Suggested-by: Takashi Iwai <tiwai@suse.de>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
> 
> Applied now.  Thanks.

I would consider revert if my objection is appropriate.

				Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.