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 states properlyThis 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.
Best regards Wang Shengjiu
Takashi
diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c index 14de734d98eb..e28738b0de96 100644 --- a/src/pcm/pcm_direct.c +++ b/src/pcm/pcm_direct.c @@ -848,6 +848,7 @@ int snd_pcm_direct_resume(snd_pcm_t *pcm) snd_pcm_start(dmix->spcm); err = 0; }
- dmix->state = snd_pcm_state(dmix->spcm); snd_pcm_direct_semaphore_up(dmix, DIRECT_IPC_SEM_CLIENT); return err;
}