.. _tablet-debugging: ============================================================================== Debugging tablet issues ============================================================================== .. _tablet-capabilities: ------------------------------------------------------------------------------ Required tablet capabilities ------------------------------------------------------------------------------ To handle a tablet correctly, libinput requires a set of capabilities on the device. When these capabilities are missing, libinput ignores the device and prints an error to the log. This error messages reads :: missing tablet capabilities: xy pen btn-stylus resolution. Ignoring this device. or in older versions of libinput simply: :: libinput bug: device does not meet tablet criteria. Ignoring this device. When a tablet is rejected, it is usually possible to verify the issue with the ``libinput record`` tool. - **xy** indicates that the tablet is missing the ``ABS_X`` and/or ``ABS_Y`` axis. This indicates that the device is mislabelled and the udev tag ``ID_INPUT_TABLET`` is applied to a device that is not a tablet. A bug should be filed against `systemd `__. - **pen** or **btn-stylus** indicates that the tablet does not have the ``BTN_TOOL_PEN`` or ``BTN_STYLUS`` bit set. libinput requires either or both of them to be present. This indicates a bug in the kernel driver or the HID descriptors of the device. - **resolution** indicates that the device does not have a resolution set for the x and y axes. This can be fixed with a hwdb entry, locate and read the `60-evdev.hwdb `__ file on your machine and file a pull request with the fixes against `systemd `__.