Bug 101222 - [amd-staging] No DisplayPort surround sound with DC on RX 480 (HDMI works)
Summary: [amd-staging] No DisplayPort surround sound with DC on RX 480 (HDMI works)
Status: RESOLVED MOVED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/AMDgpu (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-05-28 21:11 UTC by James Le Cuirot
Modified: 2019-11-19 08:18 UTC (History)
3 users (show)

See Also:
i915 platform:
i915 features:


Attachments
/proc/asound/HDMI/codec#0 (5.12 KB, text/plain)
2017-05-28 21:11 UTC, James Le Cuirot
no flags Details
/proc/asound/HDMI/eld#0.0 (441 bytes, text/plain)
2017-05-28 21:11 UTC, James Le Cuirot
no flags Details
/proc/asound/HDMI/eld#0.1 (1016 bytes, text/plain)
2017-05-28 21:12 UTC, James Le Cuirot
no flags Details
Some interesting dmesg output (9.27 KB, text/plain)
2017-05-28 21:16 UTC, James Le Cuirot
no flags Details
fix (697 bytes, patch)
2017-06-22 15:08 UTC, Mikko Autio
no flags Details | Splinter Review

Description James Le Cuirot 2017-05-28 21:11:20 UTC
Created attachment 131555 [details]
/proc/asound/HDMI/codec#0

I've been trying amd-staging on and off for a while in the hope of getting HDMI/DP surround sound working. There seems to be very few people trying amd-staging and even fewer trying surround sound as I haven't seen a single mention of it anywhere. Is it even supposed to work yet?

Stereo output is working but multi-channel LPCM only appears on my receiver as stereo and AC3 pass-through doesn't work at all. I had all this working on the same system with my old HD 4670 and I've made do with S/PDIF from my on-board sound in the meantime. I've tried directly with ALSA and via PulseAudio.

The latest kernel I've tried is 4.11 with b382281b45ec359deeeeef715b182322f4fa9566. I've found alsa-lib and friends can make a difference in the past so I just tried 1.1.4.

I'll attach some details. Note that I have a stereo monitor plugged into the HDMI port and my receiver in the first DisplayPort. I obviously select the right output when testing!
Comment 1 James Le Cuirot 2017-05-28 21:11:54 UTC
Created attachment 131556 [details]
/proc/asound/HDMI/eld#0.0
Comment 2 James Le Cuirot 2017-05-28 21:12:10 UTC
Created attachment 131557 [details]
/proc/asound/HDMI/eld#0.1
Comment 3 James Le Cuirot 2017-05-28 21:16:24 UTC
Created attachment 131558 [details]
Some interesting dmesg output
Comment 4 Mikko Autio 2017-06-22 15:08:51 UTC
Created attachment 132140 [details] [review]
fix

Attached patch fixes multi-channel HDMI audio on my RX 460.
Comment 5 Harry Wentland 2017-06-22 15:30:19 UTC
Thanks, Mikko. Looks good. Do you want to send a patch to amd-gfx? If not I'll create a patch with description and title for it.
Comment 6 James Le Cuirot 2017-06-22 21:29:50 UTC
(In reply to Mikko Autio from comment #4)
> Attached patch fixes multi-channel HDMI audio on my RX 460.

I was about to shower you with praise but sadly that patch made no difference here. :(
Comment 7 Mikko Autio 2017-06-23 03:02:04 UTC
(In reply to James Le Cuirot from comment #6)
> (In reply to Mikko Autio from comment #4)
> > Attached patch fixes multi-channel HDMI audio on my RX 460.
> 
> I was about to shower you with praise but sadly that patch made no
> difference here. :(

Maybe there is something else broken with DisplayPort audio?

I have my receiver plugged into HDMI port of my RX 460 and my TV is plugged into my receiver. Multi-channel audio over HDMI was working fine even without the patch (including AC3/DTS pass-through), but only up to 5.1 channels. Anything over 5.1 channels appeared as stereo on my receiver.

With the patch 7.1 LPCM and DTS-HD/TrueHD pass-through are now working fine.
Comment 8 Mikko Autio 2017-06-23 03:03:03 UTC
(In reply to Harry Wentland from comment #5)
> Thanks, Mikko. Looks good. Do you want to send a patch to amd-gfx? If not
> I'll create a patch with description and title for it.

I'll let you think of a description and title for it ;)
Comment 9 James Le Cuirot 2017-06-23 21:00:40 UTC
(In reply to Mikko Autio from comment #7)
> (In reply to James Le Cuirot from comment #6)
> > (In reply to Mikko Autio from comment #4)
> > > Attached patch fixes multi-channel HDMI audio on my RX 460.
> > 
> > I was about to shower you with praise but sadly that patch made no
> > difference here. :(
> 
> Maybe there is something else broken with DisplayPort audio?

Yes! I switched the outputs around (one was just using an adapter) and now it works! I really should have tried that sooner. This arrangement is fine for me as the monitor is just stereo anyway.

LPCM works and so does ALSA pass-through but PulseAudio is refusing to do pass-through for some reason. I've had it working in the past but I can live with that for now.
Comment 10 Martin Peres 2019-11-19 08:18:13 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/drm/amd/issues/179.


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