Commit a8317763 authored Oct 04, 2016 by Ben Gamari Committed by Dmitry Torokhov Oct 04, 2016

Input: ALPS - handle 0-pressure 1F events



While a button is held SS5 hardware will give us single-finger packets
with x, y, and pressure equal to zero. This causes annoying jumps in
pointer position if a touch is released while the button is held. Handle
this by claiming zero contacts to ensure that no position events are
provided to the user.

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Ben Gamari <ben@smart-cactus.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

parent 4777ac22

drivers/input/mouse/alps.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -1198,7 +1198,13 @@ static int alps_decode_ss4_v2(struct alps_fields *f,
		f->mt[0].x = SS4_1F_X_V2(p);
		f->mt[0].y = SS4_1F_Y_V2(p);
		f->pressure = ((SS4_1F_Z_V2(p)) * 2) & 0x7f;
		f->fingers = 1;
		/*
		* When a button is held the device will give us events
		* with x, y, and pressure of 0. This causes annoying jumps
		* if a touch is released while the button is held.
		* Handle this by claiming zero contacts.
		*/
		f->fingers = f->pressure > 0 ? 1 : 0;
		f->first_mp = 0;
		f->is_mp = 0;
		break;