From: Jason Gerecke Date: Tue, 7 May 2019 18:53:22 +0000 (-0700) Subject: HID: wacom: Sync INTUOSP2_BT touch state after each frame if necessary X-Git-Tag: v5.1.12~105 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ffca8e0c6a69f7cd869e34f92ee697d21f9da511;p=thirdparty%2Fkernel%2Fstable.git HID: wacom: Sync INTUOSP2_BT touch state after each frame if necessary commit 69dbdfffef20c715df9f381b2cee4e9e0a4efd93 upstream. 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: 4922cd26f03c ("HID: wacom: Support 2nd-gen Intuos Pro's Bluetooth classic interface") Cc: # 4.11+ Signed-off-by: Jason Gerecke Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index e848445236d86..09b8e4aac82f4 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)