SUMMARY I noticed texture flickering in a few cases. STEPS TO REPRODUCE Scenario 1. 1. Create a horizontal panel with a few application icons. 2. Move the mouse over the icons on the panel. Try moving fast enough so that tooltips with the icon name don't appear. Scenario 2. 1. Invoke logout/reboot/shutdown effect. OBSERVED RESULT Scenario 1. The panel texture is flickering. I can see its opacity vary, as well as contents jitter during the flickering. Scenario 2. The screen dimming effect of the logout/reboot/shutdown animation has flickering opacity. After the animation completion, sometimes the effect darkens the desktop contents more than usual, and then after a fraction of a second (or maybe after I move the mouse) opacity gets restored to usual (which looks like desktop contents become less darkened). While the animation is in progress, the logout/reboot/shutdown icons flicker. EXPECTED RESULT No flickering should happen. SOFTWARE/OS VERSIONS Linux: Kubuntu 19.04 KDE Plasma Version: 5.15.4 KDE Frameworks Version: 5.56.0 Qt Version: 5.12.2 Mesa: 19.0.2 X.org: 1.20.4 ADDITIONAL INFORMATION I'm seeing this on a laptop with Intel Haswell iGPU (i915 driver). I've also seen the problem with logout/reboot/shutdown effect on a different machine, also with Kubuntu 19.04, but with Nvidia GPU (430.09 driver). Not the panel flickering, though.
Created attachment 120326 [details] Screencast showing the problem I've recorded a video showing the problem. The problem reproduces with different plasma themes: Breeze, Breeze Light, Kubuntu.
I think, I found a workaround. In xorg.conf, for the Intel iGPU, I've added this option: Option "DRI" "3" In my case, I have Intel iGPU section in a separate file /etc/X11/xorg.conf.d/20-intel.conf, which now looks like this: Section "Device" Identifier "card0" Driver "intel" Option "Backlight" "intel_backlight" Option "DRI" "3" BusID "PCI:0:2:0" EndSection
Is this still happening to you in Plasma 5.21?
(In reply to Nate Graham from comment #3) > Is this still happening to you in Plasma 5.21? It's not released in Kubuntu yet, so I can't test.
May be a KWin issue?
Can you test again?
The logout scenario reproduces on my machine with a Nvidia GPU: Operating System: Kubuntu 21.10 KDE Plasma Version: 5.22.5 KDE Frameworks Version: 5.86.0 Qt Version: 5.15.2 Kernel Version: 5.13.0-21-lowlatency (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-2600K CPU @ 3.40GHz Memory: 15.6 GiB of RAM Graphics Processor: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 Nvidia driver: 470.86 As the darken effect is animated, the power off icon in the center sometimes flicker. This is much less obvious than it was initially when I reported the problem, and sometimes is not visible at all, but still happens.
On my Intel GPU system this no longer reproduces, neither the panel flickering nor the logout screen. Operating System: Kubuntu 21.10 KDE Plasma Version: 5.22.5 KDE Frameworks Version: 5.86.0 Qt Version: 5.15.2 Kernel Version: 5.13.0-21-lowlatency (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-4700HQ CPU @ 2.40GHz Memory: 15.5 GiB of RAM Graphics Processor: Mesa DRI Intel® HD Graphics 4600
Ok great, thanks!