Patch "HID: wacom: Do not completely map WACOM_HID_WD_TOUCHRINGSTATUS usage" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

HID: wacom: Do not completely map WACOM_HID_WD_TOUCHRINGSTATUS usage

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
hid-wacom-do-not-completely-map-wacom_hid_wd_touchringstatus-usage.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jason Gerecke <[email protected]>
Date: Fri, 4 Aug 2017 15:35:14 -0700
Subject: HID: wacom: Do not completely map WACOM_HID_WD_TOUCHRINGSTATUS usage

From: Jason Gerecke <[email protected]>

commit 8d411cbf46e515ca2b7ceb3d2b3f43e22813edac upstream.

The WACOM_HID_WD_TOUCHRINGSTATUS usage is a single bit which tells us whether the touchring is currently in use or not. Because we need to reset the axis value to 0 when the finger is removed, we call 'wacom_map_usage' to ensure that the required type/code values are associated with the usage. The 'wacom_map_usage' also sets up the axis range and resolution, however, which is not desired in this particular case.

Although xf86-input-wacom doesn't do really do anything with the ring's range or resolution, the libinput driver (for Wayland environments) uses these values to provide proper angle indications to userspace.

---
 drivers/hid/wacom_wac.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

@@ -1846,7 +1846,13 @@ static void wacom_wac_pad_usage_mapping(
 		features->device_type |= WACOM_DEVICETYPE_PAD;
 		break;
 	case WACOM_HID_WD_TOUCHRINGSTATUS:
-		wacom_map_usage(input, usage, field, EV_ABS, ABS_WHEEL, 0);
+		/*
+		 * Only set up type/code association. Completely mapping
+		 * this usage may overwrite the axis resolution and range.
+		 */
+		usage->type = EV_ABS;
+		usage->code = ABS_WHEEL;
+		set_bit(EV_ABS, input->evbit);
 		features->device_type |= WACOM_DEVICETYPE_PAD;
 		break;
 	case WACOM_HID_WD_BUTTONCONFIG:

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/hid-wacom-do-not-completely-map-wacom_hid_wd_touchringstatus-usage.patch