| Summary: | Black window flashes after restarting compositing | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Lastique <andysem> |
| Component: | compositing | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED UNMAINTAINED | ||
| Severity: | normal | ||
| Priority: | NOR | ||
| Version First Reported In: | 5.18.5 | ||
| Target Milestone: | --- | ||
| Platform: | Kubuntu | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
| Attachments: | KWin config file (~/.config/kwinrc) | ||
This bug was reported against an outdated version of KWin. We have made many changes since the. If the issue persists in newer versions can you reopen the bug report updating the version number. |
Created attachment 132317 [details] KWin config file (~/.config/kwinrc) SUMMARY After restarting compositing in KWin (for example, due to a Nvidia driver crash or via a hotkey or VT switch), contents of some windows begin flashing black upon certain activities. For example, when "Open/Save File" dialog window opens, Firefox window in the background momentarily turns black and then back to normal. This is not tied to any particular applications or GUI toolkits. I've seen black flashes with both GTK and Qt applications. This is also not reliably reproducible and may not show right away after restarting compositing. STEPS TO REPRODUCE 1. Restart KWin compositing. 2. Try interacting with desktop, like open or close windows, resize windows, etc. OBSERVED RESULT Some windows begin flashing black. EXPECTED RESULT No black flashing is expected. SOFTWARE/OS VERSIONS Linux: Kubuntu 20.04 x86_64, X11 KDE Plasma Version: 5.18.5 KDE Frameworks Version: 5.68.0 Qt Version: 5.12.8 Nvidia driver: 455.26.1 (also reproducible with other versions) ADDITIONAL INFORMATION In my /etc/environment I have: KWIN_TRIPLE_BUFFER=1 KWIN_USE_BUFFER_AGE=0 KWIN_PERSISTENT_VBO=1 __GL_YIELD="USLEEP" __GL_SYNC_TO_VBLANK=1 KWin is started with the command line `__GL_THREADED_OPTIMIZATIONS=0 kwin_x11 "$@"`. The __GL_THREADED_OPTIMIZATIONS env variable has no effect on the issue, it is just used to reduce CPU consumption by kwin_x11. The usual workaround is to restart KWin by running `kwin_x11 --replace` from krunner.