[alsa-devel] snd_pcm_wait won't return

Dennis Borgmann dennis.borgmann at googlemail.com
Wed Jun 16 08:42:31 CEST 2010

Dear alsa-devel list!

I already posted this on alsa-users, but this list doesn't seem to be
that crowded so I will give it a try in here...

I am using the alsa-lib in one of my projects and within this project,
there is a call for snd_pcm_wait() on a machine, that plays sound. The
call itself looks like this:

snd_pcm_wait( pcm_handle, 1000 );

A few steps before, I had the timeout set to unlimited (-1), which
sometimes did not return at all. Now, it sometimes returns after the
timeout, but in result I cannot write anything to the soundcard anymore.
This error is reproducable if there are many underruns in a row. Since
this program runs in a network environment and receives its data from a
datastream, I sometimes cannot avoid those underruns.

So, what could be the error, that leads to alsa not responding anymore?
I can only revitalize the system after such an error by rebooting the
whole system (well, at least I did not find another solution like
snd_pcm_prepare or snd_pcm_recover).

Which additional informations do you need? What is there, that I can
provide in addition? Could this be an alsa-bug?

Kind regards,

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