Commit 30ebb7fa authored Sep 19, 2012 by Tai-hwa Liang Committed by Dmitry Torokhov Sep 19, 2012

Input: sentelic - filter out erratic movement when lifting finger

When lifing finger off the surface some versions of touchpad send movement
packets with very low coordinates, which cause cursor to jump to the upper
left corner of the screen. Let's ignore least significant bits of X and Y
coordinates if higher bits are all zeroes and consider finger not touching
the pad.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43197


Reported-and-tested-by: Aleksey Spiridonov <leks13@leks13.ru>
Tested-by: Eddie Dunn <eddie.dunn@gmail.com>
Tested-by: Jakub Luzny <limoto94@gmail.com>
Tested-by: Olivier Goffart <olivier@woboq.com>
Signed-off-by: Tai-hwa Liang <avatar@sentelic.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

parent 59d1f5c4

drivers/input/mouse/sentelic.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -721,6 +721,17 @@ static psmouse_ret_t fsp_process_byte(struct psmouse *psmouse)

		switch (psmouse->packet[0] >> FSP_PKT_TYPE_SHIFT) {
		case FSP_PKT_TYPE_ABS:

		if ((packet[0] == 0x48 \|\| packet[0] == 0x49) &&
		packet[1] == 0 && packet[2] == 0) {
		/*
		* Ignore coordinate noise when finger leaving the
		* surface, otherwise cursor may jump to upper-left
		* corner.
		*/
		packet[3] &= 0xf0;
		}

		abs_x = GET_ABS_X(packet);
		abs_y = GET_ABS_Y(packet);