From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: [PATCH] alps: Fix finger jumps on lifting 2 fingers on v7 touchpad Date: Wed, 20 May 2015 11:16:53 +0200 Message-ID: <1432113413-7007-1-git-send-email-hdegoede@redhat.com> Return-path: Received: from mx1.redhat.com ([209.132.183.28]:49577 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752846AbbETJQ4 (ORCPT ); Wed, 20 May 2015 05:16:56 -0400 Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: Peter Hutterer , Benjamin Tissoires , linux-input@vger.kernel.org, Hans de Goede 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 --- 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 745921f..9bc4343 100644 --- a/drivers/input/mouse/alps.c +++ b/drivers/input/mouse/alps.c @@ -949,6 +949,11 @@ 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: -- 2.4.1