Bug 445338

Summary: Visual glitch in form of narrow horizontal stripes across animated parts of the screen
Product: [Plasma] kwin Reporter: Andrei Rybak <rybak.a.v>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 5.23.2   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: camera footage of the glitch

Description Andrei Rybak 2021-11-11 14:19:57 UTC
Created attachment 143450 [details]
camera footage of the glitch

SUMMARY
Sometimes (I'm not sure what's causing this), there are visual glitches when there is some movement on screen. It looks like a bunch narrow (1 pixel in height) horizontal stripes.

STEPS TO REPRODUCE
No known way to reproduce.

OBSERVED RESULT
See camera footage – this glitch does not show up in videos recorded via SimpleScreenRecorder for me.

EXPECTED RESULT
No visual glitches like this one.

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.23
KDE Plasma Version: 5.23.2
KDE Frameworks Version: 5.86.0
Qt Version: 5.15.3
Kernel Version: 5.11.0-38-generic (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 7.7 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620

ADDITIONAL INFORMATION
Reporting this as kwin bug, because workaround `kwin --replace` seems to fix it for me. I've observed this for quite some time now, so it is not new to the KDE version 5.23.2, and probably also existed in 5.22.* and 5.21.*.
Comment 1 Andrei Rybak 2023-05-17 23:33:59 UTC
Since 2021, I have

1. upgraded up to KDE 5.27.5.
2. changed my V-sync settings
3. upgraded my monitor

I haven't been able to reproduce the bug, so there's no sense in keeping this bug open.