SUMMARY Automatic adaptive sync leaves the desktop in a VRR state after closing the fullscreen application that triggered it. This persists even after disabling adaptive sync in display settings, but is fixed by switching to another refresh rate. STEPS TO REPRODUCE 1. Enable adaptive sync 2. Observe desktop is properly vsynced still 3. Open a fullscreen application 4. Observe application enables VRR as expected 5. Close fullscreen application 5. Observe desktop is stuck in a VRR state (as seen by monitor OSD display and flickering behavior) OBSERVED RESULT Desktop is stuck in incorrect VRR state until the refresh rate is switched to another and back. EXPECTED RESULT Desktop returns to normal vsynced state after closing application SOFTWARE/OS VERSIONS KDE Plasma Version: 5.27.11 KDE Frameworks Version: 5.115.0 Qt Version: 5.15.12 Kernel Version: 6.7.9-204.fsync.fc39.x86_64 Graphics Platform: Wayland ADDITIONAL INFORMATION
In this bad state, switching vrr to "never" has no effect but "always" and then "never" gets back to a good state.
Still present with kwin 6.0.4.1 Tested on Arch (fully up to date as of today). If the system is booted while the setting is set to Adaptive Sync=Never on both monitors the behavior is correct (even if it's bad). If one monitor is set to adaptive sync = automatic and the other is set to never, the flicker will manifest on both monitors I have tried minimizing every open application on every monitor, closing everything on every monitor. Only restarting the session or adjusting the refresh rate manually in "Display Properties" after changing the refresh rate will correct the undesirable behavior.
This is a driver bug, please report it to your graphics vendor (at https://gitlab.freedesktop.org/drm/amd/-/issues for AMD, https://forums.developer.nvidia.com/c/gpu-graphics/linux for NVidia)