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@xxxxxxx] > Sent: Wednesday, May 11, 2016 3:13 PM > To: Shengjiu Wang > Cc: perex@xxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx > 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@xxxxxxx] > > > > > Sent: Tuesday, May 10, 2016 4:22 PM > > > > > To: Shengjiu Wang > > > > > Cc: perex@xxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx > > > > > 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@xxxxxxxxxxxxx> > > > > > > > > > > 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@xxxxxxx> > > > > Date: Fri Oct 30 17:13:50 2015 +0100 > > > > > > > > pcm: dmix: Handle slave PCM xrun and unexpected states > properly > > > > > > > > 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 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
