SUMMARY Sometimes, when the screen locks due to timeout, the screen will stay black with a movable cursor. The only way out is switching to a TTY and killing kwin_wayland, which will cause most applications to crash. STEPS TO REPRODUCE 1. Wait for the screen to lock. 2. Move the mouse OBSERVED RESULT Sometimes, the screen will stay black and it will not be possible to unlock the session normally. EXPECTED RESULT A password prompt should appear. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Fedora Linux 40 KDE Plasma Version: 6.0.4 KDE Frameworks Version: 6.1.0 Qt Version: 6.7.0 ADDITIONAL INFORMATION Running "loginctl unlock-sessions" or killing plasmashell does not help to recover, only killing kwin_wayland. One of the times it happened, after killing kwin_wayland, I logged out and I was not able to log back in until I rebooted.
Sounds bad. Does this happen if you lock and then immediately try to prevent locking by moving the cursor right after it locks? Or does it happen when the auto-lock happens and then you don't supply any kind of interaction for a while?
It happens when I move the mouse immediately after it locks to prevent locking. In "EXPECTED RESULT", I should have said that I expected the session to unlock after moving the mouse, not a password prompt. My "Lock screen automatically" and "Dim automatically" settings are set to the same value (usually 5 minutes, now 1 minute for testing). "Allow unlocking without password" is set to 5 seconds.
Another detail. I can reproduce this with an AMD GPU, but not with an Intel GPU. OpenGL vendor string: AMD OpenGL renderer string: AMD Radeon RX 7800 XT (radeonsi, navi32, LLVM 18.1.1, DRM 3.57, 6.8.8-300.fc40.x86_64) OpenGL core profile version string: 4.6 (Core Profile) Mesa 24.0.6 OpenGL core profile shading language version string: 4.60 OpenGL vendor string: Intel OpenGL renderer string: Mesa Intel(R) UHD Graphics 630 (CFL GT2) OpenGL core profile version string: 4.6 (Core Profile) Mesa 24.0.6 OpenGL core profile shading language version string: 4.60
I can reproduce this 100%, and I have an Intel iGPU. Steps: 1. Let the screen locj naturally (does not happen if yo lock it with Meta+L 2. Move the mouse within the gracelock period (5 seconds by default) Boom, black screen with movable cursor. Looks like it's Bug 476567, which has returned. Marking as a duplicate of it. *** This bug has been marked as a duplicate of bug 476567 ***