Created attachment 175752 [details] legion go kscreen-doctor output, kscreen.log, and edid-decode SUMMARY On many handheld PCs with internal displays, such as the Lenovo Legion Go and ROG Ally, KScreen under KWin Wayland reports invalid scaled panel resolutions as valid. If any of these non-valid resolutions are selected, major paneel issues occur such as artifacting across the entire display or half of the panel going blank. If users happen to hit save on any of these resolutions, then they need to totally reset their Plasma display settings in order to get a usable internal panel again. STEPS TO REPRODUCE 1. On a handheld PC, such as the Legion Go or ROG Ally, launch Plasma under Wayland 2. In System Settings -> Display Configuration, select one of the non-default modes in the drop down menu for resolution OBSERVED RESULT Artifacts across the entire panel or portions of the panel going blank EXPECTED RESULT Valid scaled image or no selectable invalid resolutions listed. SOFTWARE/OS VERSIONS Linux/KDE Plasma: SteamOS 3.7, Linux 6.8.12-valve3-1-neptune-68 KDE Plasma Version: 6.2.2 KDE Frameworks Version: 6.7.0 Qt Version: 6.8.0 ADDITIONAL INFORMATION Under Plasma X11, invalid monitor modes are not listed at all so this is not an issue.
Do you happen to have a Steamdeck you can see if it reproduces on?
> Under Plasma X11, invalid monitor modes are not listed at all so this is not an issue That's a surprise. Generated modes were added to KWin because people expected it, coming from Xorg...
(In reply to Nate Graham from comment #1) > Do you happen to have a Steamdeck you can see if it reproduces on? I do have a Steam Deck, just checked and it is locked to 800x1280(10:16) as the only available mode on both X11 and Wayland on the same SteamOS image (testing off the staging branch, as KDE 6.2.2 is currently deployed on it)
I was able to test a little more thoroughly today, and I can briefly summarize the differences I see between Plasma 5.27.10 and Plasma 6.2.2 Wayland sessions in case it helps. Legion Go, which has a rotated 1600x2560@144hz panel similar to the Steam Deck (uses `fbcon=rotate:3` instead of :1): SteamOS Main, Plasma 5.27.10 - selecting any scaled resolution leads to total garbage on the panel, regardless of which is selected SteamOS staging, Plasma 6.2.2 - selecting any scaled resolution leads to an incorrectly vertically cropped desktop, where the entire desktop will take up ~1/3 of the internal panel, directly in the middle. The panel remains blank on either side of this portion. Orientation does not affect the cropping. changing the resolution will further crop the desktop. I've seen reports of connecting/disconnecting external monitors sometimes causing total garbage on the Legion Go's internal panel up to Plasma 6.2.0 after disconnection, but I have not been able to personally reproduce this yet. ROG Ally X, which has a horizontal 1920x1080@120hz VRR display: SteamOS Main, Plasma 5.27.10 - selecting any scaled resolution leads the display being split in half vertically, with one side remaining totally blank SteamOS staging, Plasma 6.2.2 - selecting any scaled resolution seems to work as you would expected - both screen dimensions and scaling seem to line up with the System settings. I'd need to do some further validation but so far this works correctly. This covers the non-Deck handhelds that I personally own. I'm unsure how other handhelds from manufacturers like MSI, GPD or Ayaneo handle this.
Ah. This bug has already been fixed then, with https://invent.kde.org/plasma/kwin/-/merge_requests/5874 The problem of > selecting any scaled resolution leads to an incorrectly vertically cropped desktop, where the entire desktop will take up ~1/3 of the internal panel, directly in the middle is a driver bug, which you can report at https://gitlab.freedesktop.org/drm/amd/-/issues
Thanks, bug report filed here: https://gitlab.freedesktop.org/drm/amd/-/issues/3769