Bug 80162 - center and lfe channels screwed up on suspend
Summary: center and lfe channels screwed up on suspend
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Radeon (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact:
Depends on:
Reported: 2014-06-17 20:09 UTC by Pierre Ossman
Modified: 2014-06-18 19:46 UTC (History)
0 users

See Also:
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i915 features:


Description Pierre Ossman 2014-06-17 20:09:11 UTC
Started out in the kernel bugzilla as I figured this was an alsa driver problem:


> AMD HDMI audio output. Works fine until I suspend the machine. After resume, center channel is silent and LFE channel is sent as center.
> Massive issue as the center channel is the most used one of all in multichannel audio sources. :/
> Unloading just snd_hda_intel and reloading it seems to work around the issue.

The verdict there though was that it didn't seem like the audio end was doing anything wrong, so it must be something in the graphics driver.

Comment 1 Alex Deucher 2014-06-17 21:10:35 UTC
AFAIK, video driver doesn't have anything to do with the mappings.  Does forcing a modeset after resume help?  E.g., change the mode with xrandr and see if that helps.  Maybe some of the AMD specific verbs in the hda driver need to be reset?

Comment 2 Pierre Ossman 2014-06-18 19:42:55 UTC
Thanks. Going through the vendor verbs revealed the issue. Multichannel mode was getting reset on suspend, and was not properly reinitialised by the driver on resume.

Will prepare a patch for the ALSA folks. I guess you can close this bug entry as invalid.

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