Commit 10ddadfa authored Jul 30, 2024 by Jason Gerecke Committed by Greg Kroah-Hartman Sep 04, 2024

HID: wacom: Defer calculation of resolution until resolution_code is known



commit 1b8f9c1fb464968a5b18d3acc1da8c00bad24fad upstream.

The Wacom driver maps the HID_DG_TWIST usage to ABS_Z (rather than ABS_RZ)
for historic reasons. When the code to support twist was introduced in
commit 50066a04 ("HID: wacom: generic: Add support for height, tilt,
and twist usages"), we were careful to write it in such a way that it had
HID calculate the resolution of the twist axis assuming ABS_RZ instead
(so that we would get correct angular behavior). This was broken with
the introduction of commit 08a46b4190d3 ("HID: wacom: Set a default
resolution for older tablets"), which moved the resolution calculation
to occur *before* the adjustment from ABS_Z to ABS_RZ occurred.

This commit moves the calculation of resolution after the point that
we are finished setting things up for its proper use.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Fixes: 08a46b4190d3 ("HID: wacom: Set a default resolution for older tablets")
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 11b4b0e6

drivers/hid/wacom_wac.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1830,12 +1830,14 @@ static void wacom_map_usage(struct input_dev input, struct hid_usage usage,
		int fmax = field->logical_maximum;
		unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);
		int resolution_code = code;
		int resolution = hidinput_calc_abs_res(field, resolution_code);
		int resolution;

		if (equivalent_usage == HID_DG_TWIST) {
		resolution_code = ABS_RZ;
		}

		resolution = hidinput_calc_abs_res(field, resolution_code);

		if (equivalent_usage == HID_GD_X) {
		fmin += features->offset_left;
		fmax -= features->offset_right;