On Thu, Sep 21, 2017 at 08:41:13AM -0700, Jason Gerecke wrote: > 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?
There's two cases with these devices: 1) device ships with a single touch firmware load by default 2) device can be updated with a multi touch firmware load. So it's either hid-generic or hid-multitouch, depending on what you've configured and of course different PIDs to discern between them. I'll take a look at handling both in the kernel. -Matt _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel
