Bug 1042996

Summary: random flickering on AMD RX480
Product: [openSUSE] openSUSE Tumbleweed Reporter: Jan Matejek <jmatejek>
Component: X.OrgAssignee: E-mail List <xorg-maintainer-bugs>
Status: RESOLVED FIXED QA Contact: E-mail List <xorg-maintainer-bugs>
Severity: Normal    
Priority: P3 - Medium    
Version: Current   
Target Milestone: ---   
Hardware: Other   
OS: Other   
Whiteboard:
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---
Attachments: hwinfo output
Xorg.0.log for amdgpu
Xorg.0.log for modesetting

Description Jan Matejek 2017-06-06 20:31:46 UTC
Created attachment 727864 [details]
hwinfo output

this is actually a Leap 42.2 system with a Tumbleweed kernel and Xorg from X11:Xorg repository
(because otherwise on 42.2 the RX480 doesn't work at all?)

in Xwindows, the desktop randomly flickers. The whole screen blinks for a frame or two, or maybe some artifacts are shown that disappear immediately. This happens intermittently, intervals ranging from a couple minutes to a couple seconds.
I couldn't tie this to a particular action, the screen even flickers when left completely alone and nothing is visibly changing.

This doesn't depend on whether a compositor is turned on or off, nor on the rendering API the compositor is using. I have tested KDE Plasma (my primary desktop), MATE and IceWM, and the flickering is present in all of them (and in the KDM login screen as well), although it seems to happen less frequently without compositor in KDE and even less frequently in IceWM.
So, somehow tied to "graphical intensity" of what is going on?
Comment 1 Stefan Dirsch 2017-06-07 08:52:13 UTC
Don't know which X driver you're using. Options are "modesetting" and "amdgpu".
You may want to switch to the other one by installing/uninstalling xf86-video-amdgpu package.
Comment 2 Jan Matejek 2017-06-07 10:38:54 UTC
I'm seeing the same behavior on both drivers. "modesetting" seems to flicker less frequently, although that could be just pure chance, it is still random.

(Also same artifacts on *some* cases of window resizing under Plasma compositor with default effect. Not sure if this is related.
(Said artifacts seem to be distorted pieces of what is actually displayed on screen))

Does this mean the problem is in the kernel driver, or do the drivers share code?
Comment 3 Jan Matejek 2017-06-07 10:39:31 UTC
Created attachment 727954 [details]
Xorg.0.log for amdgpu
Comment 4 Jan Matejek 2017-06-07 10:39:57 UTC
Created attachment 727955 [details]
Xorg.0.log for modesetting
Comment 5 Jan Matejek 2017-06-07 10:43:12 UTC
for completeness, this does not happen in Windows, so it's not a purely hardware problem either.
Comment 6 Jan Matejek 2017-06-07 11:02:47 UTC
wellp.
after updating the kernel today, the flickering seems to be gone.
i'll reopen if i run into a problem again