SUMMARY Starting with Linux kernel version 6.16-rc1, I have started seeing kwin_wayland soft-freeze with "kwin_wayland_drm: Atomic test failed! Permission denied" errors in journalctl. Switching to tty doesn't work ~ but REISUB does, upon which I can restart the compositor. The freezing appears to happen upon turning off the screen and turning it back on ~ along with other apparently random moments during normal system usage when kwin_wayland tries to make such a test and just can't keep going, so it locks up entirely. STEPS TO REPRODUCE 1. Install Linux 6.16-rc1 2. Start kwin_wayland 3. Turn off screen, turn on screen, maybe perfect atomic test somehow? 4. Profit? Not sure whether this is the only cause. OBSERVED RESULT Compositor soft-freeze with no restart or crash EXPECTED RESULT Functioning normally? SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.4.80 KDE Frameworks Version: 6.16.0 Qt Version: 6.9.1 Kernel Version: 6.16.0-rc1-1-custom-bcachefs-git-00060-ge1bce19af73a (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 7800X3D 8-Core Processor Memory: 32 GiB of RAM (30.4 GiB usable) Graphics Processor 1: AMD Radeon RX 7900 XTX Graphics Processor 2: AMD Radeon Graphics Manufacturer: ASRock Product Name: X670E Pro RS
Created attachment 182375 [details] journalctl entries from soft-frozen boot
Also comes in the "kwin_wayland_drm: Atomic test failed! Invalid argument" flavour too, apparently. Common underlying issue too, probably.
Created attachment 182376 [details] 6.16-rc1 config for testing
Appears fixed with 6.16-rc2. Not kwin_wayland's bug, apparently.