Re: [PATCH] HID: input: fix uclogic tablets

[José Expósito]

Hi Benjamin,

On Mon, Aug 22, 2022 at 08:22:47AM +0200, Benjamin Tissoires wrote:
> commit 87562fcd1342 ("HID: input: remove the need for HID_QUIRK_INVERT")
> made the assumption that it was the only one handling tablets and thus
> kept an internal state regarding the tool.
> 
> Turns out that the uclogic driver has a timer to release the in range
> bit, effectively making hid-input ignoring all in range information
> after the very first one.
> 
> Fix that by having a more rationale approach which consists in forwarding
> every event and let the input stack filter out the duplicates.

Apologies for the delayed response, I was on holiday.

Tested on the affected device (HUION H640P) and I can confirm that the
issue is fixed.

I also tested in other non-Wacom tablets and they keep working as
expected.

Best wishes,
Jose

> Reported-by: Stefan Hansson <newbie13xd@xxxxxxxxx>
> Fixes: 87562fcd1342 ("HID: input: remove the need for HID_QUIRK_INVERT")
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
>  drivers/hid/hid-input.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> index 48c1c02c69f4..871a185a0f1f 100644
> --- a/drivers/hid/hid-input.c
> +++ b/drivers/hid/hid-input.c
> @@ -1532,7 +1532,10 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
>  			 * assume ours
>  			 */
>  			if (!report->tool)
> -				hid_report_set_tool(report, input, usage->code);
> +				report->tool = usage->code;
> +
> +			/* drivers may have changed the value behind our back, resend it */
> +			hid_report_set_tool(report, input, report->tool);
>  		} else {
>  			hid_report_release_tool(report, input, usage->code);
>  		}
> -- 
> 2.37.1
>