When this patch is applied the screens connected to displayport through my dock just cycles off and on again continuously.
When I revert that commit it starts working as intended again.
I am running a Thinkpad X260.
That would be
Author: Libin Yang <firstname.lastname@example.org>
Date: Mon Sep 19 18:24:41 2016 -0700
drm/i915: start adding dp mst audio
We need to revert.
Kim, what if you keep commit 3708d5e082 but revert this one instead:
Author: Pandiyan, Dhinakaran <email@example.com>
Date: Wed Sep 21 13:02:48 2016 -0700
drm/i915/dp: DP audio API changes for MST
It seems this issue is caused by FIFO xrun.
However, it is OK when we are using 720p resolution.
Please attach dmesg with drm.debug=0x14 if you can reproduce the issue.
(In reply to Dhinakaran Pandiyan from comment #4)
> Please attach dmesg with drm.debug=0x14 if you can reproduce the issue.
drm.debug=0xe or drm.debug=14. It's a bitmap. 0x14 is not helpful.
Will try to do that later this evening. Worst-case I'll do it tomorrow.
Regarding the resolution I am running 1920x1200, 1200x1920 and 1920x1080.
I am having trouble in confirming that the revert is fixing the issue. The display does not cycle off and on continuously for me, instead the external displays go off and come up immediately when the cursor moves from one screen to another. However, this does not happen every time cursor crosses the screen boundary. IOW, the screen blinking is tied to the cursor movement. Reverting these patches is not helping.
I am using a DP MST hub that connects to two external DP monitors @2560x1440. The eDP is set to 1920x1200.
Can you please provide more details about when the screen start cycling off and on?
I just trying to reproduce the issue, after compiling and installing the mentioned commit i got the 2 displays on the MST on the system but physically without output signal.
Perform hard-reset and unplug-plug of the MST hub having signal again on 3 monitors, 2 on MST hub, same display configuration.
Hardware: Intel(R) Core(TM) i5-6260U CPU @ 1.80GHz
OS: Ubuntu 16.04 (Clean).
Kernel : commit f931894194b9395313d1c34f95ceb8d91f49790d
(In reply to Kim Lidström from comment #6)
> Will try to do that later this evening. Worst-case I'll do it tomorrow.
> Regarding the resolution I am running 1920x1200, 1200x1920 and 1920x1080.
Could you share your Graphic configuration? Mesa, Xorg, libva etc?
I was finally able to reproduce the issue with a SKL NUC w/ i5-6260U CPU @ 1.80GHz
The flickers are triggered by underruns, which are in turn triggered when we set the enable bit in HSW_AUD_PIN_ELD_CP_VLD (inactive bit zero).
I tested it by setting the inactive bit in the same register along with the enable bit, this case did not trigger flickers.
So, it looks like the MST case needs to be handled differently.
It doesn't seem like you have an obviously correct fix yet. Please send the revert or do I have to?
Sorry for the unresponsiveness. Sickness combined with family and a broken ISP :)
You seem to have discovered something, although I did not experience "flickering" but more like the monitors lost the signal for a few seconds, turned off and then the signal returned. Continuously. Maybe that's what you meant, though?
Also, regarding my graphic configuration I am runnig xorg 1.18.4, xf86-video-intel 20160823 and I libva 1.7.1 installed (I saw Elio asking for that, although I don't know about the graphics stack to know where it fits in)
Created attachment 126821 [details] [review]
I might have a fix just in time. Can someone try this? This is not a full solution, the existing code needs a bit of rework
Created attachment 126822 [details] [review]
Revert for " drm/i915/dp: DP audio API changes for MST"
Created attachment 126823 [details] [review]
Revert for "drm/i915: start adding dp mst audio"
The fix did not work for one of the configurations. So, I have attached the reverts here.
Dhinakaran, please send to the list.
Author: Dhinakaran Pandiyan <firstname.lastname@example.org>
Date: Wed Sep 28 23:55:04 2016 -0700
Revert "drm/i915: start adding dp mst audio"
Kim, please reopen if the problem persists on current drm-intel-nightly. Thanks.