Bug 11214 - (int-188625) Media Player [bridge_work-que] battery drain
: Media Player [bridge_work-que] battery drain
Status: NEW
Product: Media player
: 5.0:(10.2010.19-1)
: N900 Maemo
: Unspecified normal with 3 votes (vote)
: ---
Assigned To: unassigned
: media-player-bugs
  Show dependency tree
Reported: 2010-08-29 23:28 UTC by Brad Bosch
Modified: 2011-02-06 18:40 UTC (History)
3 users (show)

See Also:

This sample video file reproduces the bug (976.56 KB, application/octet-stream)
2010-08-29 23:30 UTC, Brad Bosch


You need to log in before you can comment on or make changes to this bug.

Description Brad Bosch (reporter) 2010-08-29 23:28:03 UTC
(Settings > General > About product)

(Explain in detail what you do (e.g. tap on OK) and what you see (e.g. message
Connection Failed appears))
0. Copy a slightly corrupt video (which still plays) such as junk.avi to a
folder in MyDocs
1. Notice first that CPU usage is low when idle (e.g using Conky)
2. Start Media Player
3. Choose Video (Video thumbs are shown)
4. Leave Media Player

When idle the device the CPU utilization should remain near 0

- The CPU utilization will periodically spike to near 100%
- gst-video-thumbnailerd still running heavy for a few seconds (guess its
- after a few seconds a bridge_work-que process shows up running with high cpu
load and maybe keeping the CPU from getting into an idle state, thus draining


NOTE:  This is apparently the same problem as in bug 9084
Comment 1 Brad Bosch (reporter) 2010-08-29 23:30:40 UTC
Created an attachment (id=3053) [details]
This sample video file reproduces the bug

Position the thumbnail to the beginning of the video to see the bug.
Comment 2 Andre Klapper maemo.org 2010-08-30 13:29:33 UTC
Comment 3 John Perez 2010-09-16 23:28:48 UTC
I have no idea what causes this, but it could be related to pausing a video,
switching to another application, then switching back and resuming the video. 
I get consistent bridge_work-que 100% cpu spikes and fast battery drain,
heating of the n900.
Comment 4 Pavan 2011-02-06 15:38:20 UTC
*** This bug has been confirmed by popular vote. ***
Comment 5 Alexander Bokovoy 2011-02-06 18:40:57 UTC
Video thumbnailer uses DSP-based decoders provided as part of GStreamer
framework. These decoders run their code on DSP and bridge-related kernel
thread is used for coordinating access to DSP for user space processes.

High CPU load is most likely a manifestation of CPU waiting for data access on
the frames decoded by DSP as bridge driver purges cache L1/L2 caches in order
to guarantee data correctness when exchanges between CPU and other devices
(DSP) happen.