I'm having issues with Linux 4.2 RC5 with the Displayport audio being deeper then normal. Doesn't seem to happen with 4.1.3 with a backported patch from https://bugzilla.kernel.org/attachment.cgi?id=183611
Created attachment 184611 [details] Patch Reverting Commit 7726e72b3d6879ee5fc743a230eb6f5afa12844b Seems to fix my issues.
Are you sure that's the right commit? That commit shouldn't have any affect on DP audio. All it does is move the check for monitor audio support from radeon_atom_encoder_mode_set() into radeon_audio_mode_set(). It doesn't change the hw programming at all.
Yes, I just double checked. With the commit, the displayport audio is warped.
Huh seems to be the EDID detection. Windows/xrandr --verbose seem to get the EDID right but get-edid doesn't.
Replacing drm_detect_monitor_audio(radeon_connector_edid(connector)) with true seems to fix the problem.
(In reply to Maxqia from comment #5) > Replacing drm_detect_monitor_audio(radeon_connector_edid(connector)) with > true seems to fix the problem. This means the EDID from your monitor claims not to support audio.
Created attachment 185301 [details] dmesg log
It works with fglrx, also in the dmesg log it says "[drm:drm_detect_monitor_audio] Monitor has basic audio support" Which is when it should output true
Created attachment 185391 [details] Possible Patch
Created attachment 185441 [details] Updated Patch
Any Updates?
I don't see what this patch changes.
Looking back with an extra year of programming knowledge, it seems like commit 7726e72b3d6879ee5fc743a230eb6f5afa12844b doesn't do anything except add a drm_detect_monitor_audio to the hdmi audio pathway ..., before that commit only Displayport was checked for audio. Anyways, issue still present.
Created attachment 238501 [details] Explained Patch
Comment on attachment 238501 [details] Explained Patch :/ I really don't know what I'm doing... Commenting this if block fixes it... https://github.com/torvalds/linux/blob/9439b3710df688d853eb6cb4851256f2c92b1797/drivers/gpu/drm/radeon/radeon_atombios.c#L1267 That probably means that the thing setting the display clock frequency is broken in some way...
I'm having the same problem with my Tahiti GPU. This output seems to confirm that there's an EDID issue: > tail -n+1 /proc/asound/card*/eld* [...] edid_version [0x0] no CEA EDID Timing Extension block present [...] These patches touch DCE6 and such: https://lists.freedesktop.org/archives/amd-gfx/2018-October/027462.html Maybe it fixes this issue? Don't have the availability to test at the moment.