This is a note to let you know that I've just added the patch titled Input: alps - v7: sometimes a single touch is reported in mt[1] to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: input-alps-v7-sometimes-a-single-touch-is-reported-in-mt.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7091c443dda8c6c6d8e70e33452252f9ad3e7814 Mon Sep 17 00:00:00 2001 From: Hans de Goede <hdegoede@xxxxxxxxxx> Date: Thu, 18 Dec 2014 09:53:34 -0800 Subject: Input: alps - v7: sometimes a single touch is reported in mt[1] From: Hans de Goede <hdegoede@xxxxxxxxxx> commit 7091c443dda8c6c6d8e70e33452252f9ad3e7814 upstream. The v7 proto differentiates between a primary touch (with high precision) and a secondary touch (with lower precision). Normally when 2 fingers are down and one is lifted the still present touch becomes the primary touch, but some traces have shown that this does not happen always. This commit deals with this by making alps_get_mt_count() not stop at the first empty mt slot, and if a touch is present in mt[1] and not mt[0] moving the data to mt[0] (for input_mt_assign_slots). BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=86338 Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Tested-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/input/mouse/alps.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) --- a/drivers/input/mouse/alps.c +++ b/drivers/input/mouse/alps.c @@ -919,12 +919,14 @@ static void alps_get_finger_coordinate_v static int alps_get_mt_count(struct input_mt_pos *mt) { - int i; + int i, fingers = 0; - for (i = 0; i < MAX_TOUCHES && mt[i].x != 0 && mt[i].y != 0; i++) - /* empty */; + for (i = 0; i < MAX_TOUCHES; i++) { + if (mt[i].x != 0 || mt[i].y != 0) + fingers++; + } - return i; + return fingers; } static int alps_decode_packet_v7(struct alps_fields *f, @@ -970,6 +972,14 @@ static int alps_decode_packet_v7(struct else /* pkt_id == V7_PACKET_ID_MULTI */ f->fingers = 3 + (p[5] & 0x03); + /* Sometimes a single touch is reported in mt[1] rather then mt[0] */ + if (f->fingers == 1 && f->mt[0].x == 0 && f->mt[0].y == 0) { + f->mt[0].x = f->mt[1].x; + f->mt[0].y = f->mt[1].y; + f->mt[1].x = 0; + f->mt[1].y = 0; + } + return 0; } Patches currently in stable-queue which might be from hdegoede@xxxxxxxxxx are queue-3.18/input-alps-v7-ignore-new-packets.patch queue-3.18/input-alps-v7-sometimes-a-single-touch-is-reported-in-mt.patch queue-3.18/input-alps-v7-fix-finger-counting-for-2-fingers-on-clickpads.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html