Commit 9fbd67c5 authored May 07, 2019 by Jason Gerecke Committed by Greg Kroah-Hartman Jun 19, 2019

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: 4922cd26 ("HID: wacom: Support 2nd-gen Intuos Pro's Bluetooth classic interface")
Cc: <stable@vger.kernel.org> # 4.11+
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent dd1d71ad

drivers/hid/wacom_wac.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -1369,13 +1369,19 @@ 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);
		}
		}

		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)
		{
		struct input_dev *pad_input = wacom->pad_input;