#12580 NORM Future : XO-1.5 audio playback hang

Zarro Boogs per Child bugtracker at laptop.org
Tue Feb 26 14:17:09 EST 2013

#12580: XO-1.5 audio playback hang
 Reporter:  dsd     |                 Owner:  dsd           
     Type:  defect  |                Status:  new           
 Priority:  normal  |             Milestone:  Future Release
Component:  kernel  |               Version:  not specified 
 Keywords:          |           Next_action:  never set     
 Verified:  0       |   Deployment_affected:                
Blockedby:          |              Blocking:                
 Seen in Nicaragua's 12.1.0 spin. "I know my ABC" activity was running, and
 had hung, blocked trying to play a sound via gst-launch, no audio being

 The strace of that process just showed a poll loop.

 Trying to run speaker-test as root also hung before playing the first

 After killing the gst-launch process, the activity spawned another one
 which also hung. Now speaker-test (as root) would apparently cycle through
 the sounds, but there was no audible output.

 After killing the new gst-launch process, no further sounds could be
 played. speaker-test (as user) complains: unable to create IPC semaphore

 ipcs shows that the memory and semaphore was owned by root. Deleted it
 with ipcrm, and now things started playing again. Maybe me running
 speaker-test as root had screwed something up.

 Indeed just running the gst-launch command in a loop will reproduce this
 while true; do
 /usr/bin/gst-launch-0.10 filesrc
 ! oggdemux ! vorbisdec ! audioconvert ! alsasink

 Most of the time it plays the sound fine, sometimes it doesn't give any
 errors but produces no audible output, and sometimes it hangs.

Ticket URL: <http://dev.laptop.org/ticket/12580>
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