On Fri, 2 Mar 2012, Nikolai Kondrashov wrote:
> Allow array field values out of range as per HID 1.11 specification,
> section 6.2.25:
>
> Rather than returning a single bit for each button in the group, an
> array returns an index in each field that corresponds to the pressed
> button (like keyboard scan codes). An out-of range value in and array
> field is considered no controls asserted.
>
> Apparently, "and" above is a typo and should be "an".
>
> This fixes at least Waltop tablet pen clicks - otherwise BTN_TOUCH is never
> released.
>
> The relevant part of Waltop tablet report descriptors is this:
>
> 0x09, 0x42, /* Usage (Tip Switch), */
> 0x09, 0x44, /* Usage (Barrel Switch), */
> 0x09, 0x46, /* Usage (Tablet Pick), */
> 0x15, 0x01, /* Logical Minimum (1), */
> 0x25, 0x03, /* Logical Maximum (3), */
> 0x75, 0x04, /* Report Size (4), */
> 0x95, 0x01, /* Report Count (1), */
> 0x80, /* Input, */
>
> Signed-off-by: Nikolai Kondrashov <spbnick@xxxxxxxxx>
> ---
>
> I hope this could get into the 3.3 release, otherwise at least Waltop tablets
> would be useless.
>
> drivers/hid/hid-input.c | 9 +++++++--
> 1 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> index 9333d69..627850a 100644
> --- a/drivers/hid/hid-input.c
> +++ b/drivers/hid/hid-input.c
> @@ -986,8 +986,13 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
> return;
> }
>
> - /* Ignore out-of-range values as per HID specification, section 5.10 */
> - if (value < field->logical_minimum || value > field->logical_maximum) {
> + /*
> + * Ignore out-of-range values as per HID specification,
> + * section 5.10 and 6.2.25
> + */
> + if ((field->flags & HID_MAIN_ITEM_VARIABLE) &&
> + (value < field->logical_minimum ||
> + value > field->logical_maximum)) {
> dbg_hid("Ignoring out-of-range value %x\n", value);
> return;
> }
Nikolai, thanks a lot for the quick analysis and fix. I have now applied
it and will be sending it to Linus shortly.
--
Jiri Kosina
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
