SUMMARY After turning off the screens, big graphical glitches happen, and the performance is poor. STEPS TO REPRODUCE 1. Use the "turn off the screens" feature. 2. Turn the screens back on. OBSERVED RESULT The cursor stutters. After a while, performance degradation becomes very important. There are many graphical glitches (windows being redrawn incorrectly, when trying to move the windows, the move operation would fail). I couldn't do much on my desktop. EXPECTED RESULT None of the above. SOFTWARE/OS VERSIONS Operating System: CachyOS Linux KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.20.0 Qt Version: 6.10.1 Kernel Version: 6.18.0-3-cachyos (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION
In my triple monitor setup, side monitors also go black after 10 seconds of turning the monitors back on. This did not happen in 6.5.3.
Does it happen on all the screens, or only on some of them? What kind of GPU does the system have? Does it help to roll back the kernel or the drivers?
Created attachment 187512 [details] example of graphical glitch
I attached two pictures, one of the graphical glitch I experienced, and the other, the original image. The screen was blanking at a fast inconsistent interval between the glitched version and the normal version. Does it happen on all the screens, or only on some of them? > The poor performance I had was happening on all screens, but some screens had different and more severe graphical glitches. > The screens turning black only happen on left and right monitors. > Tonight, after testing to try to reproduce the degradation, I couldn't manage to reproduce it as bad as last night. Perhaps the degradation increases in severity over time or after a number of screen off -> screen on cycles. What kind of GPU does the system have? GPU : AMD RX 9070 XT My screen setup : Left : 1080p 60hz, 150% scaling, 10 bit colors. Middle : 2160p 240hz with DSC (display stream compression), 150% scaling, 10 bit colors. Right : 1080p 60hz, 100% scaling, 10 bit colors. Does it help to roll back the kernel or the drivers? > Using LTS kernel of my distro (6.12.60-2-cachyos-lts) helps. It seems to resolve the issue. I still can see some unusual and new graphical glitches with my cursor, like a second cursor being drawn until I move and do stuff with my cursor, but the performance seems fine. > Didn't try rolling back mesa drivers. This is a bit too advanced/risky for me at the moment and I don't have time to dive into learning how to do it. Additionnal information : I found a consistent way to trigger the left and right screens turning black, on the latest kernel. -Have firefox maximized on middle monitor. -Turn screens off. -Turn screens back on. -Using the window decoration, drag the firefox window to make it windowed. => The left and right screens should turn black. This does not happen on LTS kernel. Another degradation was being unable to grab and move windows. The cursor was moving and being redrawn, but I couldn't do much. Side note : -I have a minor graphical glitch that appeared with kde plasma 6.5's release (that seems to be tied to something in the kernel) where my left 1080p 150% scaled window's desktop background image would jump up and down a pixel when I moved my cursor to the screen. Also, when I right clicked on the desktop to bring up the context menu. On the LTS kernel, this does not happen. May or may not be related to the other issues mentioned here.
After further testing, the performance degradation and graphical glitches also happen on the LTS kernel.
Created attachment 187514 [details] Video example of flickering visual glitch. Had to log out of plasma session to make it stop. Desktop was unusable.
The performance degradation and visual glitches appear to be fixed with the patch done for bug https://bugs.kde.org/show_bug.cgi?id=513151 I still have some other bugs happening, so I'll close this bug report and open new ones for them.