Guidelines and HOWTOs/Bug triaging/Tricky bugs
Multi-screen issues
Multi-screen issues can be caused by multiple parts of the software stack.
Screen is not detected or turned on at all
These issues are mostly in KWin; assign them to `kwin - multi-monitor` and triage further:
Possible cause | Information to request to rule it out or confirm it |
---|---|
KWin not noticing it | request the output of `kscreen-doctor -o` |
Bad cable (rare) | Try a different cable, or try the same screen/cable combination on another device |
After login, wake-from-sleep, or screen connection/disconnection, desktops or panels are on the wrong screen, or a screen has a black background and can't be right-clicked, but the user can move the cursor and app windows there
This means that somehow the mapping of desktop/panel to screen has gotten messed up. Possibilities:
Possible cause | Information to request to rule it out or confirm it |
---|---|
"Primary Screen" assignment has moved to the wrong screen | common` and continue triaging. |
Desktops or panels are not following "Primary Screen" or screen priority assignments | desktop containment` and ask them to diff their `~/.config/plasma-org.kde.plasma.desktop-appletsrc` file before and after it happens, and attach the diff |
User disabled the Kscreen2 service | Re-enable it if it's been disabled in System Settings > Startup & Shutdown > Background Services |
Screen configuration UI does not reflect reality or has a bug in it
These are issues in the KScreen KCM; assign them to `systemsettings | kcm_kscreen`.
App windows don't launch on the expected screen
Possible cause | Information to request to rule it out or confirm it |
---|---|
User is on X11 or the app in question is using XWayland and the window always opens on a specific screen, rather than on the screen with the cursor | The app is either forcing its window to open on the primary screen, or else remembering its prior window position. Not a bug. |
Window always opens on the screen with the cursor instead of some other location where the user wants it to open | Window is a native-Wayland window or it's an X11/XWayland window that doesn't implement position memory, and so in either case, it falls back to the KWin window placement setting. Not a bug. |
Desktop icon positions get reset
TODO
Graphical corruption or visual freezes
TODO