SUMMARY KWin effects that involve blur and animated transitions flicker and appear grainy and pixelated on a screen that is attached to a Thunderbolt 3 dock. On the built-in screen of my laptop, they appear smooth and blurred as they should. It's hard to take videos or screenshots of KWin effects with Spectacle or OBS, but a phone video showing the effect on both monitors is here: https://youtu.be/ELo-a4dDKh0 The laptop is a Thinkpad X1 Yoga, the dock in question is a Lenovo Thunderbolt 3 dock. The bug appears only on Wayland. It has been around for a while, it's not a 5.24 regression. STEPS TO REPRODUCE 1. Place the mouse on the screen attached to the Thunderbolt dock 2. Invoke the virtual desktop switcher OR a KWin effect that involves animated transitions (tested with Cover Switch and Flip Switch) OBSERVED RESULT Animations and transitions flicker and appear grainy and pixelated, instead of smooth and blurred. EXPECTED RESULT The effects should look smooth and blurred everywhere. SOFTWARE/OS VERSIONS Operating System: openSUSE Tumbleweed 20220207 KDE Plasma Version: 5.24.0 KDE Frameworks Version: 5.90.0 Qt Version: 5.15.2 Kernel Version: 5.16.5-1-default (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i7-8550U CPU @ 1.80GHz Memory: 15.5 GiB of RAM Graphics Processor: Mesa Intel® UHD Graphics 620 ADDITIONAL INFORMATION
*** Bug 449961 has been marked as a duplicate of this bug. ***
Applies to the Overview effect as well. I had reported earlier as bug 449961, without realizing that the behaviour there is monitor-specific.
> Graphics Processor: Mesa Intel® UHD Graphics 620 I wonder if this was caused by a recent Mesa regression, whose symptoms line up with what you're describing. Fabian, do yo know if the fix for https://gitlab.freedesktop.org/mesa/mesa/-/issues/5731 has been shipped in Tumbleweed yet?
(In reply to Nate Graham from comment #3) > > Graphics Processor: Mesa Intel® UHD Graphics 620 > I wonder if this was caused by a recent Mesa regression, whose symptoms line > up with what you're describing. > > Fabian, do yo know if the fix for > https://gitlab.freedesktop.org/mesa/mesa/-/issues/5731 has been shipped in > Tumbleweed yet? FWICT, it's part of 21.3.6, which should be part of the next snapshot, 20220211.
(In reply to Fabian Vogt from comment #4) > FWICT, it's part of 21.3.6, which should be part of the next snapshot, 20220211. OK, when that lands I will test again and report.
The Mesa update has fixed the issue. Thank you!