Hi Takashi
After adding your patch, I find another regression issue.
The alsa-lib may stop at
snd_pcm_write_areas() snd_pcm_wait_nocheck()
with suspend and resume test.
The reason is that:
In the beginning of playback, before the snd_pcm_dmix_start() is called, the system enter suspend. After resume, snd_pcm_direct_resume() update the dmix->state, and dmix->state is 3 (RUNNING, because the dmix->spcm is in RUNNING from snd_pcm_dmix_open()).
So in snd_pcm_write_areas() the state is RUNNING, then snd_pcm_start() will never be called, after a while, alsa-lib will stop at the snd_pcm_wait_nocheck() for the kernel will not wake up the timer.
Best regards Wang shengjiu
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, May 11, 2016 3:13 PM To: Shengjiu Wang Cc: perex@perex.cz; alsa-devel@alsa-project.org Subject: Re: [PATCH] pcm: Don't store the state for SND_PCM_STATE_SUSPENDED
On Wed, 11 May 2016 08:24:55 +0200, Shengjiu Wang wrote:
Hi
On Wed, 11 May 2016 04:28:41 +0200, Shengjiu Wang wrote:
Hi
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Tuesday, May 10, 2016 4:22 PM To: Shengjiu Wang Cc: perex@perex.cz; alsa-devel@alsa-project.org Subject: Re: [PATCH] pcm: Don't store the state for SND_PCM_STATE_SUSPENDED
On Tue, 10 May 2016 09:45:46 +0200, Shengjiu Wang wrote:
The resume function don't update the dmix->state, if store
SUSPENDED
state in snd_pcm_dmix_state, the write function after resume
will
return error -ESTRPIPE, because the snd_pcm_write_areas()
will
check
the state of the pcm device. This patch remove the store SND_PCM_STATE_SUSPENDED state
operation
for dmix,dshare,dsnoop.
Signed-off-by: Shengjiu Wang shengjiu.wang@freescale.com
What's the exact problem you're seeing on surface? Could
illustrate
how the bug is triggered and how to reproduce easily? It'll
make
easier to understand what you're trying to fix.
thanks,
Takashi
The aplay endlessly print " Suspended. Trying resume. Done." if
suspend
and resume in the middle of playback. Which is caused by this
patch.
commit 8985742d91dbdd74b2f605374207473393454fff Author: Takashi Iwai tiwai@suse.de Date: Fri Oct 30 17:13:50 2015 +0100
pcm: dmix: Handle slave PCM xrun and unexpected statesproperly
This patch store the SUSPENDED state to dmix->state, but after
resume
the dmix->state still is SUSPENDED, next write function will
check
the
state, if state is SUSPENDED, it will return -ESTRPIPE, then the
aplay
will print another " Suspended. Trying resume. Done." Then
repeat
this
behavior again and again.
Thanks, this is exactly what I wanted to see in the changelog! It's rather a regression, and it should be clearly mentioned.
Now about your fix: the problem is not about setting the correct state at suspending. It is suspended, so setting the right state there is the correct behavior. However, the counterpart, the
resume,
is the culprit of this bug. It misses the restore of the shadow state.
Does the patch below work instead?
Yes, it is workable.
Great, now I pushed the fix to git tree. Thanks for your quick test!
Takashi