On Thu, Sep 21, 2017 at 7:00 AM, Matt Porter <mpor...@konsulko.com> wrote: > On Thu, Sep 21, 2017 at 10:59:08AM +0200, Hans de Goede wrote: >> Hi, >> >> On 19-09-17 18:41, Matt Porter wrote: >> > The Chalkboard Electronics HID Touchscreen is classified as >> > a tablet device by systemd udev because it has BTN_TOOL_PEN >> > support. It also reports a resolution of 0 for both X and Y >> > axes in absinfo. This causes libinput to reject it as an >> > invalid tablet device. >> > >> > This quirk reclassifies the device as a touchscreen which >> > allows it to be added as a valid input device. >> > >> > Signed-off-by: Matt Porter <mpor...@konsulko.com> >> >> Have you considered adding special handling for this device >> to the kernel's hid drivers ? The hid subsys has sub drivers >> for device specific handling and if the device never actually >> has a pen, then the right fix would be to not make the kernel >> export this. Note I assume this is for a so called >> "smart" whiteboard for in classes ? If that is the case then >> the device may actually have a pen/stylus like device in >> some configuration. Some of these smart boards have what >> are basically empty whiteboard-marker in multiple colors >> and the device may report these as different styluses ... > > I hadn't really considered that since this userspace fixup > basically follows the pattern I see for other devices in > systemd's hwdb. Just to clarify, these are not "smartboard" > style devices. They are typical 7-14" touchscreen displays > with HDMI/USB interface from https://www.chalk-elec.com/ > > The updated patch for this is at > https://github.com/systemd/systemd/pull/6880 based on Peter's > earlier comments. It could be solved in the kernel as you > suggest, however it appears that usually that approach is for > very different hid devices with custom protocols (e.g. > logitech-hidpp). I could suppress the pen tool and update absinfo > in a hid-chalkboard.c if that's preferred. There could be an > advantage here for those that aren't using systemd udev. > > -Matt
What kernel driver gets bound to the device? I would expect hid-multitouch for a generic multitouch touchscreen, but I don't believe that driver ever exposes BTN_TOOL_PEN. Perhaps a quirk simply needs to be refined or defined? Jason --- Now instead of four in the eights place / you’ve got three, ‘Cause you added one / (That is to say, eight) to the two, / But you can’t take seven from three, / So you look at the sixty-fours.... _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel
