SUMMARY Every time I use my 21:9 monitor (LG 29WK500) with an AMD GPU and a distro with KDE severe graphicals glitches,compromising the use of the system. Tested with KDE Neon user edition 18.04 and Kubuntu 18.04 on these rigs PC 1: Intel Core 2 Duo P8600 AMD RADEON HD 4350 RAM 4 GB PC 2: Ryzen 5 1600 AMD RADEON RX 580 RAM 16 GB Using the monitor with another DE or OS or NVIDIA GPU doesn't seem to be any problem. STEPS TO REPRODUCE 1. Using a distro with KDE and an AMD GPU 2. Attach to the PC a 21:9 monitor OBSERVED RESULT Severe graphical glitches compromise the usage of the system EXPECTED RESULT Normal use SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Neon 18.04/Kubuntu 18.04 (available in About System) KDE Plasma Version: 5.16.4 KDE Frameworks Version: 5.61.0 Qt Version: 5.12.3 ADDITIONAL INFORMATION N/A
Can you be more specific about those glitches? I've been using an LG 29EA93 21:9 screen without a problem. How did you connect the screen? I assume it's 2560x1080 which exceeds the 1920x1080 supported by standard DVI and VGA cables. Does this happen on other desktops, too? I don't think this is a problem on KDE's side.
(In reply to Kai Uwe Broulik from comment #1) > Can you be more specific about those glitches? I've been using an LG 29EA93 > 21:9 screen without a problem. > How did you connect the screen? I assume it's 2560x1080 which exceeds the > 1920x1080 supported by standard DVI and VGA cables. > Does this happen on other desktops, too? I don't think this is a problem on > KDE's side. The monitor has only HDMI so I use that. No issues on Ubuntu 18.04,Fedora 18.04 or Windows 10 1809
I added a video to describe the problem
Created attachment 122272 [details] Graphical glitch KDE on 21:9 monitor
Interesting. I've seen similar glitches on one of my 4K screens, the one plugged in via HDMI. I still think this is a cable issue, though. Re-assigning KWin. Maybe it does more full-sized repaints which require more bandwith on the cable making glitches more likely.
(In reply to Kai Uwe Broulik from comment #5) > Interesting. I've seen similar glitches on one of my 4K screens, the one > plugged in via HDMI. I still think this is a cable issue, though. > Re-assigning KWin. Maybe it does more full-sized repaints which require more > bandwith on the cable making glitches more likely. I tried 4 different cables,so the problem is not that. Is that something that can be solved?
Are you using X11 or Wayland?
(In reply to Vlad Zahorodnii from comment #7) > Are you using X11 or Wayland? KDE/Wayland
Looks like a hardware or driver issue. Please file a bug report upstream.
(In reply to Vlad Zahorodnii from comment #9) > Looks like a hardware or driver issue. Please file a bug report upstream. I found an identical problem here https://bugs.freedesktop.org/show_bug.cgi?id=102646
Awesome!
(In reply to Vlad Zahorodnii from comment #11) > Awesome! I don't understand how to apply the patch on kde neon, is there a direct link to the solution?
What do you mean?
(In reply to Vlad Zahorodnii from comment #13) > What do you mean? Where is the code for the patch on an Ubuntu based system?
I'm not sure that I understand what you're asking. The upstream bug report has some patches but how to apply them on Ubuntu based system I don't know because I use Arch.
Why is this reopened? Did you try the patches?