ADDITIONAL TESTING: DISPLAYLINK DRIVER COMPARISON I also tested the DisplayLink driver (v6.2.0-30) on the same hardware before identifying the Silicon Motion chipset. The behavior was identical, confirming this is a Wayland compositor issue rather than a Silicon Motion-specific problem.
Test Results: DisplayLink driver installed: Service started successfully EVDI modules loaded: card2-card5 created in /dev/dri/ KWin behavior: Immediately closed EVDI cards xrandr --listmonitors: No new displays visible Journal Evidence: evdi: [I] (card2) Closed by Task 2167 (kwin_wayland) evdi: [I] (card3) Closed by Task 2167 (kwin_wayland) Conclusion: Both DisplayLink and Silicon Motion drivers create EVDI virtual displays that KWin probes and rejects on Wayland. This suggests a systemic issue with EVDI support in KWin 6.5.6 (Wayland) rather than a driver-specific bug. **SUSPECTED ROOT CAUSE** KWin on Wayland lacks explicit support for EVDI virtual displays created by the Silicon Motion driver. While the kernel module builds successfully, the compositor probes the device and rejects it, likely due to missing Wayland protocol support or a regression in KWin 6.5.6 regarding EVDI. -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to kwin in Ubuntu. https://bugs.launchpad.net/bugs/2145155 Title: Integrated USB display fails to register as device To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kwin/+bug/2145155/+subscriptions -- kubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs
