SUMMARY Display Configuration does not support weird resolutions on a non-standard secondary display in X11 and claims it is in Wayland. STEPS TO REPRODUCE 1. Launch X11 Plasma session with an unusual secondary display (e.g. an 800x1280 display masquerading as 1080x1920) over HDMI 2. `echo $XDG_SESSION_TYPE`: should return `x11` 3. Navigate to Display Configuration OBSERVED RESULT Note that Resolution is fixed at one value (no dropdown) with the note: "Using unsupported resolutions was possible in the Plasma X11 session, but they were never guaranteed to work and are not available in this Plasma Wayland session." even though the current session is X11, not Wayland. EXPECTED RESULT Multiple resolution options available even though they may not be supported by the display natively. Absence of a warning that "unsupported resolutions are not supported in Wayland" in an X11 session. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.27.4 KDE Frameworks Version: 5.104.0 Qt Version: 5.15.8 Kernel Version: 6.2.10-arch1-1 (64-bit) Graphics Platform: X11 Processors: Intel® Core™ i5-8250U ADDITIONAL INFORMATION Linked KWin issue: https://invent.kde.org/plasma/kwin/-/issues/144 Similar issue reported (not shared on bugs.kde.org): https://www.reddit.com/r/openSUSE/comments/u68bo3/154_plasma_fixed_at_low_res_thinks_im_on_wayland/
This particular monitor seems to be so defective that it doesn't work in any mode on half the devices I've tested it on, so maybe ignore this bug.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kscreen/-/merge_requests/202
Git commit 785148788d4841b5dc8c54293dc7e347a568299f by Xaver Hugl. Committed on 09/04/2023 at 16:03. Pushed by zamundaaa into branch 'master'. kcm: remove text about unsupported modes on Wayland It's not true anymore and can confuse the user, as it can also be shown on X11 M +1 -1 kcm/package/contents/ui/OutputPanel.qml https://invent.kde.org/plasma/kscreen/commit/785148788d4841b5dc8c54293dc7e347a568299f
*** Bug 472877 has been marked as a duplicate of this bug. ***