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

commit f77810f744139572a63e5a85ab6a8c10c2d44fb1 upstream.

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: 6d09085b38e5 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index d049239256a268b467c6fe565f3a516d2d609ab1..2bd1a43021c924b8a9268a29b3fcc18c0774fe57 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2522,11 +2522,12 @@ 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);