From 72eceab743cf61082357068e0686ffac66fe47e5 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 20 May 2015 14:37:41 -0700 Subject: [PATCH] Input: alps - fix finger jumps on lifting 2 fingers on v7 touchpad On v7 touchpads sometimes when 2 fingers are moved down on the touchpad until they "fall of" the touchpad, the second touch will report 0 for y (max y really since the y axis is inverted) and max x as coordinates, rather then reporting 0, 0 as is expected for a non touching finger. This commit detects this and treats these touches as non touching. See the evemu-recording here: https://bugzilla.redhat.com/attachment.cgi?id=1025058 BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1221200 Signed-off-by: Hans de Goede Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/alps.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c index e6708f6efb4d..7752bd59d4b7 100644 --- a/drivers/input/mouse/alps.c +++ b/drivers/input/mouse/alps.c @@ -941,6 +941,11 @@ static void alps_get_finger_coordinate_v7(struct input_mt_pos *mt, case V7_PACKET_ID_TWO: mt[1].x &= ~0x000F; mt[1].y |= 0x000F; + /* Detect false-postive touches where x & y report max value */ + if (mt[1].y == 0x7ff && mt[1].x == 0xff0) { + mt[1].x = 0; + /* y gets set to 0 at the end of this function */ + } break; case V7_PACKET_ID_MULTI: -- 2.20.1