HID: wacom: Fix logic used for 3rd barrel switch emulation

When support was added for devices using an explicit 3rd barrel switch,
the logic used by devices emulating this feature was broken. The 'if'
statement / block that was introduced only handles the case where the
button is pressed (i.e. 'barrelswitch' and 'barrelswitch2' are both set)
but not the case where it is released (i.e. one or both being cleared).
This results in a BTN_STYLUS3 "down" event being sent when the button
is pressed, but no "up" event ever being sent afterwards.

This patch restores the previously-used logic for determining button
states in the emulated case so that switches are reported correctly
again.

Link: https://github.com/linuxwacom/xf86-input-wacom/issues/292
Fixes: 70a4fbe10b70 ("HID: wacom: Adding Support for new usages")
CC: stable@vger.kernel.org #v5.19+
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Tested-by: Joshua Dickens <joshua.dickens@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 77486962a773f5a197d151d62ed5e387f1890570..0f3d57b42684671337ef615b479728629ed148d2 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2520,11 +2520,12 @@ static void wacom_wac_pen_report(struct hid_device *hdev,
 
        if (!delay_pen_events(wacom_wac) && wacom_wac->tool[0]) {
                int id = wacom_wac->id[0];
-               if (wacom_wac->features.quirks & WACOM_QUIRK_PEN_BUTTON3 &&
-                   wacom_wac->hid_data.barrelswitch & wacom_wac->hid_data.barrelswitch2) {
-                       wacom_wac->hid_data.barrelswitch = 0;
-                       wacom_wac->hid_data.barrelswitch2 = 0;
-                       wacom_wac->hid_data.barrelswitch3 = 1;
+               if (wacom_wac->features.quirks & WACOM_QUIRK_PEN_BUTTON3) {
+                       int sw_state = wacom_wac->hid_data.barrelswitch |
+                                      (wacom_wac->hid_data.barrelswitch2 << 1);
+                       wacom_wac->hid_data.barrelswitch = sw_state == 1;
+                       wacom_wac->hid_data.barrelswitch2 = sw_state == 2;
+                       wacom_wac->hid_data.barrelswitch3 = sw_state == 3;
                }
                input_report_key(input, BTN_STYLUS, wacom_wac->hid_data.barrelswitch);
                input_report_key(input, BTN_STYLUS2, wacom_wac->hid_data.barrelswitch2);