https://bugs.kde.org/show_bug.cgi?id=522419
Ron Viers <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |[email protected] --- Comment #2 from Ron Viers <[email protected]> --- Same here on Plasma 6.6.6 (Kubuntu 26.04, kwin-wayland 6.6.6, libinput 1.31.1, Qt 6.10.2), also a Wacom Intuos4 PTK-840, but with the tablet mapped to the WHOLE workspace. So the trigger is not partial mapping as such: the pen enters proximity at a workspace position that no output covers. My layout is three monitors of different heights: 1440x2560 portrait, a 2899x1631 (logical) landscape in the middle, and 1440x2560 portrait. The bounding rectangle therefore has an empty area above or below the middle monitor, and the tablet maps onto that empty area too. I logged raw evdev (pen proximity/position) and the journal for 9 days. Of 44 proximity-ins inside the empty area above the middle monitor, 35 (80%) were followed within 3 s by a dead pen: KWin's crosshair fallback cursor, no hover or clicks in any window, and Qt clients flooding "qt.qpa.wayland: Can't send tablet event with no proximity surface, ignoring". Of 1,928 proximity-ins over a real output, about 1% were followed by a failure. The kernel keeps sending events throughout (hundreds of position samples during the dead period), so the fault is above libinput. Recovery: leave proximity and re-enter over a real output (or disable/enable the device). Steps: 1. Arrange monitors so the layout's bounding box contains an area with no output (e.g. a shorter monitor between two taller ones). 2. Map the tablet to the full workspace. 3. Lift the pen out of range, then bring it into range over a point that maps into the uncovered area. 4. Move onto a window: no hover/click, crosshair cursor. Workaround that works here: fill the uncovered area with a virtual output, so every tablet position maps onto a real output: krfb-virtualmonitor --resolution 2899x929 --name pentrap --password <pw> --port <port> kscreen-doctor output.Virtual-pentrap.position.1440,1631 (and firewall the VNC port it opens). Plasma puts a desktop surface on the virtual output and the pen no longer dies there (0 failures since). This suggests KWin should handle proximity-in at a position with no output, e.g. clamp it onto the nearest output like it does for the pointer, instead of leaving the tool without a focus surface. -- You are receiving this mail because: You are watching all bug changes.
