leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
e9e8520f22
linux/drivers/input
History
Benjamin Tissoires e9e8520f22 Input: synaptics - use in-kernel tracking for reporting mt data 
The current code tries to consider all states and transitions to properly
detect which finger is attached to which slot. The code is quite huge
and difficult to read.

If the sensor manages to group the touch points but is not reliable in
giving tracking ids, we can simply use the kernel tracking method. Note
that it is already used by Cr-48 Chromebooks.

Incidentaly, this fixes a bug reported by Peter Hutterer:
"""
on the Lenovo T440, run:
evemu-record /dev/input/event4 | grep BTN_

then put one, two, three, two fingers down
when you go from 3 to 2 fingers the driver sends a spurious BTN_TOUCH 0
event:

E: 0.000000 0001 014a 0001      # EV_KEY / BTN_TOUCH            1
E: 0.000000 0001 0145 0001      # EV_KEY / BTN_TOOL_FINGER      1
E: 0.770008 0001 0145 0000      # EV_KEY / BTN_TOOL_FINGER      0
E: 0.770008 0001 014d 0001      # EV_KEY / BTN_TOOL_DOUBLETAP   1
E: 1.924716 0001 014d 0000      # EV_KEY / BTN_TOOL_DOUBLETAP   0
E: 1.924716 0001 014e 0001      # EV_KEY / BTN_TOOL_TRIPLETAP   1

.. changing from 3 to 2 fingers now

E: 3.152641 0001 014a 0000      # EV_KEY / BTN_TOUCH            0
E: 3.152641 0001 014d 0001      # EV_KEY / BTN_TOOL_DOUBLETAP   1
E: 3.152641 0001 014e 0000      # EV_KEY / BTN_TOOL_TRIPLETAP   0
E: 3.176948 0001 014a 0001      # EV_KEY / BTN_TOUCH            1

quick look in the kernel shows it's caused by hw.z going to 0 for a packet,
so probably a firmware bug. either way, it makes it hard to track BTN_TOUCH
as signal that at least one finger is down.
"""

The in-kernel tracking is enough to remove this spurious BTN_TOUCH 0.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2014-12-29 14:23:00 -08:00
..
gameport Input: initialize device counter variables with -1 2014-12-03 15:27:17 -08:00
joystick Input: initialize device counter variables with -1 2014-12-03 15:27:17 -08:00
keyboard Input: add new sun4i-lradc-keys driver 2014-12-21 18:59:21 -08:00
misc Input: add tps65218 power button driver 2014-12-27 20:43:03 -08:00
mouse Input: synaptics - use in-kernel tracking for reporting mt data 2014-12-29 14:23:00 -08:00
serio Input: initialize device counter variables with -1 2014-12-03 15:27:17 -08:00
tablet Merge branch 'wacom' into next 2014-08-06 23:31:48 -07:00
touchscreen Input: elants_i2c - remove unnecessary version.h inclusion 2014-12-29 14:08:59 -08:00
apm-power.c
evbug.c
evdev.c Input: evdev - add CLOCK_BOOTTIME support 2014-12-17 15:46:59 -08:00
ff-core.c
ff-memless.c
input-compat.c
input-compat.h
input-mt.c Input: fix used slots detection breakage 2014-08-25 14:59:48 -07:00
input-polldev.c Input: implement managed polled input devices 2014-05-14 16:40:04 -07:00
input.c Input: optimize events_per_packet count calculation 2014-12-15 21:45:55 -08:00
joydev.c Input: fix use-after-free introduced with dynamic minor changes 2012-10-22 08:50:37 +03:00
Kconfig Input: mousedev - allow disabling even without CONFIG_EXPERT 2013-10-31 08:46:07 -07:00
Makefile
matrix-keymap.c input: Export matrix_keypad_parse_of_params() 2013-04-19 00:31:13 +02:00
mousedev.c Input: mousedev - fix race when creating mixed device 2014-03-29 14:44:23 -07:00
sparse-keymap.c treewide: Fix typo in Documentation/DocBook 2014-02-19 14:58:17 +01:00