https://bugs.kde.org/show_bug.cgi?id=527428
--- Comment #23 from 720Florian <[email protected]> --- Update: Still reproducible on KWin 6.8.2; working workaround found I can confirm that this regression is still present with KWin/Plasma 6.8.2 on NixOS, NVIDIA driver 595.104.02, and an RTX 4060 Laptop GPU (AD107M). Additional findings from instrumented KWin builds: - Screenshots show the complete desktop, but the physical monitor displays only a small portion, with the remaining area black. - DRM primary planes report full-resolution framebuffers and correct source/destination rectangles. - Disabling direct scanout specifically for DP-1 did not resolve the issue. - Changing refresh rates and disabling/re-enabling outputs did not help. - Setting KWIN_USE_BUFFER_AGE=0 did not resolve the issue. - The issue persisted even after successfully switching the affected output from a 10-bit ABGR2101010 framebuffer to an 8-bit ARGB8888 framebuffer. Working workaround: In the NixOS configuration, disable SDDM Wayland: services.displayManager.sddm.wayland.enable = false; SDDM then runs on X11, while the actual KDE Plasma session continues running on Wayland. With this single change, all three monitors now work correctly, including after multiple reboots. No Plasma downgrade, NVIDIA driver downgrade, or custom KWin patches are required. This suggests that the SDDM/initial display initialization sequence may be involved, although the underlying cause has not been confirmed. Separately, I disabled the briefly appearing SDDM virtual keyboard using: services.displayManager.sddm.settings.General.InputMethod = ""; I can provide the detailed DRM snapshots and instrumented KWin logs if needed. -- You are receiving this mail because: You are watching all bug changes.
