#10168 BLOC 1.5-sof: Scratch can freeze up after playing sound

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#10168: Scratch can freeze up after playing sound
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           Reporter:  cjb       |       Owner:  cjb                
               Type:  defect    |      Status:  new                
           Priority:  blocker   |   Milestone:  1.5-software-update
          Component:  kernel    |     Version:  not specified      
         Resolution:            |    Keywords:                     
        Next_action:  diagnose  |    Verified:  0                  
Deployment_affected:            |   Blockedby:  6201               
           Blocking:            |  
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Comment(by pgf):

 current thoughts, extracted from an email message.  sorry about the
 duplication for some folks.

 {{{
 i'm looking at sqUnixSoundALSA.c from:

 http://www.squeakvm.org/cgi-bin/viewcvs.cgi/trunk/platforms/unix/vm-sound-
 ALSA/sqUnixSoundALSA.c?rev=2168&view=auto

 it's not clear to me that ignoring ESTRPIPE (if that's what was
 tried) is the right answer.  it seems that alsa's (ab)use of
 ESTRPIPE is an indication that the sound system was suspended,
 and that (for some reason) one needs to explicitly tell it to
 resume, or, failing that, to re-"prepare" it.  search for
 "ESTRPIPE" on this page:
     http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
 and if you find that description a bit opaque, try clicking
 through to the snd_pcm_resume() doc, which makes it a bit more
 clear.

 i don't know enough about how alsa really works to understand
 whether this is an alsa problem -- i haven't tried to determine
 whether alsa should be doing the resume itself (as it seems it
 should do).

 (if "suspend" and "resume" mean something different in the sound
 world than they do to the rest of the kernel, then a) that's
 unfortunate, and/or b) perhaps the problem is that kernel suspend
 shouldn't be putting alsa into state SNDRV_PCM_STATE_SUSPENDED.)
 }}}

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Ticket URL: <http://dev.laptop.org/ticket/10168#comment:10>
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