SUMMARY I have two monitors set to 144Hz, and a third which runs at 60Hz. In both SDDM and KDE (both plasma 5.X and 6.X), plugging in the third monitor (either before boot or while running) causes the two 144Hz monitors to go black, and the 60Hz monitor gets all glitchy, flashing black and not responding. Similar to https://bugs.kde.org/show_bug.cgi?id=465712, if BOTH 144Hz monitors are set to 60Hz, this setup works fine. Setting either to 60 while the other still operates at 144 also triggers the aagressive visual glitching. However, since that issue was solved and my graphical glitching is much more severe, I'm opening a separate issue. After unplugging the display again, plasma freezes, and the following shows in dmesg: Mar 07 09:30:04 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:06 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:08 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:10 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:12 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:14 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:16 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:18 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:20 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:22 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:24 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:26 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:28 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:30 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:32 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:34 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:37 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:39 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:41 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:43 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 Mar 07 09:30:45 proton kernel: nvidia-modeset: ERROR: GPU:0: Idling display engine timed out: 0x0000c67e:6:0:1173 STEPS TO REPRODUCE 1. Plug in a 60Hz monitor on a 144Hz system. OBSERVED RESULT The screens stop working as expected EXPECTED RESULT The screens work as expected SOFTWARE/OS VERSIONS Linux: 6.7.8-zen1-1-zen (64-bit) KDE Plasma Version: 6.0.1 KDE Frameworks Version: 6.0.0 Qt Version: 6.6.2 ADDITIONAL INFORMATION Displays: - 2x LG UltraGear 27GN650-B - Huion Kamvas 13 GPU: NVIDIA GeForce RTX 4080 SUPER Driver: Proprietary NVIDIA 550.54.14
This is a driver bug, please report this to NVidia.