Hi Torge,
Thanks for the patch.
On Thu, Aug 04, 2022 at 05:18:32PM +0200, Torge Matthies wrote:
> Commit f7d8e387d9ae ("HID: uclogic: Switch to Digitizer usage for
> styluses") broke input from my XP-Pen Star G640. This is because the
> "Digitizer" usage is not recognized as a valid usage for input devices.
>
> This patch changes the IS_INPUT_APPLICATION macro so that the "Digitizer"
> (HID_DG_DIGITIZER) usage is recognized as an input device usage.
>
> Fixes: f7d8e387d9ae ("HID: uclogic: Switch to Digitizer usage for styluses")
> Signed-off-by: Torge Matthies <openglfreak@xxxxxxxxxxxxxx>
> ---
> This patch could be risky, because any digitizer devices that were
> previously not treated as input devices are now used for input.
> Alternatively the linked commit could be reverted, but that would
> re-introduce the problem detailed in its commit message.
>
> include/linux/hid.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
I hesitated about this when I sent the patch you mentioned. In the end,
I didn't include any fix because the digitizer use was tested for 2
years in DIGImend, so I (wrongly) assumed that it was safe enough.
However, my initial thought was to add in uclogic_probe():
hdev->quirks |= HID_QUIRK_HIDINPUT_FORCE;
+ hdev->quirks |= HID_QUIRK_HIDINPUT_FORCE;
Let's see if we can hear more opinions, but if you are worried about
affecting other drivers, that could be a good solution.
Best wishes,
Jose
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 4363a63b9775..07803e144d98 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -883,7 +883,7 @@ static inline bool hid_is_usb(struct hid_device *hdev)
> /* We ignore a few input applications that are not widely used */
> #define IS_INPUT_APPLICATION(a) \
> (((a >= HID_UP_GENDESK) && (a <= HID_GD_MULTIAXIS)) \
> - || ((a >= HID_DG_PEN) && (a <= HID_DG_WHITEBOARD)) \
> + || ((a >= HID_DG_DIGITIZER) && (a <= HID_DG_WHITEBOARD)) \
> || (a == HID_GD_SYSTEM_CONTROL) || (a == HID_CP_CONSUMER_CONTROL) \
> || (a == HID_GD_WIRELESS_RADIO_CTLS))
>
> --
> 2.37.1
>
