SUMMARY the plasma panel and widgets would randomly freeze when kwin has explicit sync patched in STEPS TO REPRODUCE 1. use kwin with explicit sync, panel & widgets would randomly freeze, open overview a few times to unfreeze OBSERVED RESULT panel & widgets - random freeze EXPECTED RESULT To continue working correctly SOFTWARE/OS VERSIONS Operating System: EndeavourOS KDE Plasma Version: 6.0.5 KDE Frameworks Version: 6.2.0 Qt Version: 6.7.1 Kernel Version: 6.9.2-273-tkg-eevdf (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5800X3D 8-Core Processor Memory: 31,3 GiB of RAM Graphics Processor: NVIDIA GeForce RTX 3090/PCIe/SSE2 Kwin patched with explicit sync from aur: https://aur.archlinux.org/packages/kwin-explicit-sync On a side note: this also affects 6.1 beta as well
Just wanted to make a note that I was able to test other compositors which do have explicit sync(gnome & gamescope) in their own separate session and neither exhibit any problems. This was the reason I opened a different thread from my previous one and more on what the issue is more correctly.
Just a small update, I was able to trigger a reproducible state 100% on plasma 6.1 beta: Have 2 panels on 2 different monitors, both floating, the one on your second monitor to dodge windows(being hidden underneath them). Open browser on main monitor where floating panel just maximizes then super+shift+right/left arrow to move it to the monitor where it hides the panel, boom the desktop/widgets/panels freeze and opening overview a few times fixes this state. I also noticed these in my journalctl kwin_core: Failed to focus 0x4000034 (error 8) kwin_core: Failed to focus 0x3800005 (error 3) kwin_core: Failed to focus 0x3800005 (error 3)
Apologies for another reply, but I found an even easier way to reproduce it, launch mpv get it to the screen where the panel dodges windows, make it fullscreen = desktop/panels/widgets/etc have frozen, make it back windowed everything is flawless like in 6.0.5
I looked into this, and it's hanging in the NVidia driver, which waits for KWin to release a buffer that will only be released once the window is shown. This will need to be fixed in the driver