[alsa-devel] snd_pcm_avail_update() returning large values

Raymond Yau superquad.vortex2 at gmail.com
Fri May 6 05:05:04 CEST 2011

2011/5/6 Baek Chang <baeksan at ccrma.stanford.edu>

> Hi,
> Occasionally, when using pulseaudio I see the following message:
> snd_pcm_avail_update() returned a value that is exceptionally large.
> This seems to be an issue with the ALSA driver itself.  My question is how
> does snd_pcm_avail_update(), get updated? It uses hw buffer positions
> correct?  Is there an example driver that implements snd_pcm_avail_update()
> correctly and updates buffer positions correctly?
> Thanks
> Baek

You have to provide a test case which can reproduce the problem

(e.g.http://thread.gmane.org/gmane.linux.alsa.devel/78521 )

To debug,  you need to enable DEBUG_TIMING in
pulseaudio/src/modules/alsa/alsa-sink.c and

and follow

The free-glitch mode is tailor made for snd-hda-intel , so it should be the
example driver

aplay can use minimum period size without any xrun on my snd-hda-intel

aplay -Dhw:CARD=Intel  -v --period-size=32 any.wav

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