Bug 358963

Summary:	compositor often needs restart to stop flickering
Product:	[Plasma] kwin	Reporter:	cf <andybuckle>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal
Priority:	NOR
Version:	5.4.2
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	qdbus org.kde.KWin /KWin supportInformation

Description cf 2016-02-03 20:24:19 UTC

I have flickering windows. i find setting compositor to "full screen repaint" fixes it. 

Flickering returns every reboot. I go back to compositor settings, choose  something else, then go back to "full screen repaint" and it is OK again.

Reproducible: Always




OpenGL version string:                  3.0 Mesa 11.0.2
OpenGL version:                         3.0
GLSL version:                           1.30
Mesa version:                           11.0.2
X server version:                       1.17.2
Linux kernel version:                   4.2

Qt: 5.4.2
KDE Frameworks: 5.15.0

Comment 1 Thomas Lübking 2016-02-04 00:35:47 UTC

sounds more like restarting the compositor "fixes" it, try SHIFT+Alt+F12 twice instead.
Also attach the output of "qdbus org.kde.KWin /KWin supportInformation"

Comment 2 cf 2016-02-04 08:38:48 UTC

I put all compositor settings back to defaults. i was about to write how the problem had gone, then 10 min after login it came back. "SHIFT+Alt+F12 twice" fixed it (temporarily, I guess). At least I have an efficient workaround.

I renamed this report.

Comment 3 cf 2016-02-04 08:40:13 UTC

Created attachment 97002 [details]
qdbus org.kde.KWin /KWin supportInformation

Comment 4 Thomas Lübking 2016-02-04 17:17:08 UTC

bug #358646 ?!
see https://bugs.kde.org/show_bug.cgi?id=358646#c1 for a likely workaround

Comment 5 cf 2016-02-04 20:10:33 UTC

I created kwin_env.sh as described and rebooted. i still had the flickering. 

I did 'echo $KWIN_TRIPLE_BUFFER', to check if I had done everything correctly. It did not return '1' , so perhaps I messed up, though i cannot see where.

Comment 6 Thomas Lübking 2016-02-04 21:26:25 UTC

forgot to chmod +x the file?

For a quick test just run

    KWIN_TRIPLE_BUFFER=1 kwin_x11 --replace &

Should survive as many compositor restarts as you push on it.

Comment 7 cf 2016-02-04 21:33:49 UTC

I made it executable. 

my ~/.xsession-errors did not mention triple buffering, so i thought that was not the problem.

I have run the line you suggested. i will report back if it fixes the problem when it manifests.

Comment 8 Thomas Lübking 2016-02-04 22:19:27 UTC

Reg environment you may suffer from bug #352491 ?

Comment 9 cf 2016-02-05 12:28:29 UTC

    KWIN_TRIPLE_BUFFER=1 kwin_x11 --replace &

fixes it. I guess it restarts the compositor and more. So the question is does it stay fixed after that is run.

Comment 10 Thomas Lübking 2016-02-05 12:31:55 UTC

It restarts entire KWin, incl. the compositor, but keeping the environment set should downforce the issue.

Pre-emptively marking as dupe. If you see the problem despite the triple buffer path enforced, please re-open it.

*** This bug has been marked as a duplicate of bug 358646 ***