Ticket #12580 (closed defect: fixed)
XO-1.5 audio playback hang
|Reported by:||dsd||Owned by:||dsd|
|Action Needed:||test in build||Verified:||no|
|Deployments affected:||Blocked By:|
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 produced.
The strace of that process just showed a poll loop.
Trying to run speaker-test as root also hung before playing the first sound.
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 problem:
while true; do /usr/bin/gst-launch-0.10 filesrc location=/home/olpc/Activities/IKnowMyABCs.activity/sounds/es/letra_o.ogg ! oggdemux ! vorbisdec ! audioconvert ! alsasink done
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.