Re: [PATCH v4 13/14] HID: hid-multitouch: fix Win 8 protocol

From: Henrik Rydberg
Date: Wed Nov 14 2012 - 13:40:47 EST


On Wed, Nov 14, 2012 at 04:59:25PM +0100, Benjamin Tissoires wrote:
> The Win 8 protocol specify the fact that each valid touch must be reported
> within a frame until it is released.
> We can therefore use the always_valid quirk and dismiss reports when we see
> duplicate contacts ID.
>
> We recognize Win8 certified devices from their vendor feature 0xff0000c5
> where Microsoft put a signed blob in the report to check if the device
> passed the certification.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx>
> ---
> drivers/hid/hid-multitouch.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index 5f26b2f..efae60c 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -295,6 +295,18 @@ static void mt_feature_mapping(struct hid_device *hdev,
> td->maxcontacts = td->mtclass.maxcontacts;
>
> break;
> + case 0xff0000c5:
> + if (field->report_count == 256 && field->report_size == 8) {
> + /* Win 8 devices need special quirks */
> + __s32 *quirks = &td->mtclass.quirks;
> + *quirks |= MT_QUIRK_ALWAYS_VALID;
> + *quirks |= MT_QUIRK_IGNORE_DUPLICATES;
> + *quirks |= MT_QUIRK_HOVERING;
> + *quirks &= ~MT_QUIRK_NOT_SEEN_MEANS_UP;
> + *quirks &= ~MT_QUIRK_VALID_IS_INRANGE;
> + *quirks &= ~MT_QUIRK_VALID_IS_CONFIDENCE;
> + }
> + break;
> }
> }
>
> --
> 1.8.0
>

Reviewed-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>

Thanks,
Henrik
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