Commit 1b8f9c1f authored by Jason Gerecke's avatar Jason Gerecke Committed by Jiri Kosina
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HID: wacom: Defer calculation of resolution until resolution_code is known 



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 08a46b41 ("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: default avatarJason Gerecke <jason.gerecke@wacom.com>
Fixes: 08a46b41 ("HID: wacom: Set a default resolution for older tablets")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent c8000deb

drivers/hid/wacom_wac.c

+3 −1
Original line number Diff line number Diff line
@@ -1878,12 +1878,14 @@ 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;