From: Jason Gerecke <jason.gerecke@xxxxxxxxx>
The Bluetooth interface of the 2nd-gen Intuos Pro batches together four
independent "frames" of finger data into a single report. Each frame
is essentially equivalent to a single USB report, with the up-to-10
fingers worth of information being spread across two frames. At the
moment the driver only calls `input_sync` after processing all four
frames have been processed, which can result in the driver sending
multiple updates for a single slot within the same SYN_REPORT. This
can confuse userspace, so modify the driver to sync more often if
necessary (i.e., after reporting the state of all fingers).
Fixes: 4922cd26f0 ("HID: wacom: Support 2nd-gen Intuos Pro's Bluetooth classic interface")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.11+
Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx>
---
drivers/hid/wacom_wac.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index e848445236d8..09b8e4aac82f 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1371,11 +1371,17 @@ static void wacom_intuos_pro2_bt_touch(struct wacom_wac *wacom)
if (wacom->num_contacts_left <= 0) {
wacom->num_contacts_left = 0;
wacom->shared->touch_down = wacom_wac_finger_count_touches(wacom);
+ input_sync(touch_input);
}
}
- input_report_switch(touch_input, SW_MUTE_DEVICE, !(data[281] >> 7));
- input_sync(touch_input);
+ if (wacom->num_contacts_left == 0) {
+ // Be careful that we don't accidentally call input_sync with
+ // only a partial set of fingers of processed
+ input_report_switch(touch_input, SW_MUTE_DEVICE, !(data[281] >> 7));
+ input_sync(touch_input);
+ }
+
}
static void wacom_intuos_pro2_bt_pad(struct wacom_wac *wacom)
--
2.21.0
