[ltp] Strange problem with xorg, trackpoint and udev rules

Andreas Stemmer linux-thinkpad@linux-thinkpad.org
Wed, 30 Aug 2006 12:02:12 +0200


Hallo!

I decided to rework my xorg.conf and ran into a strange problem. I didn't find any help in the archives, on thinkwiki or anywhere else on the web, so perhaps someone here can tell me where my error is.

What I was trying to do is to set up udev rules for my touchpad, trackpoint and bluetooth mouse in order to configure them as seperate devices (instead of /dev/input/mice) in xorg.conf.

The rules are:

--- /etc/udev/rules.d/010_local.rules ---

BUS=="input", KERNEL=="event*", SYSFS{name}=="SynPS/2 Synaptics TouchPad", SYMLINK+="input/touchpad"

BUS=="input", KERNEL=="event*", SYSFS{name}=="TPPS/2 IBM TrackPoint", SYMLINK+="input/trackpoint"

BUS=="input", KERNEL=="event*", SYSFS{name}=="Bluetooth HID Boot Protocol Device", SYMLINK+="input/bt_mouse"

They seem to work fine since I get the right symlinks after restarting udev:

# ls -l /dev/input
lrwxrwxrwx 1 root root      6 30. Aug 11:10 bt_mouse -> event4
drwxr-xr-x 2 root root    160 30. Aug 11:09 by-path
crw------- 1 root root 13, 64 30. Aug 2006  event0
crw------- 1 root root 13, 65 30. Aug 2006  event1
crw------- 1 root root 13, 66 30. Aug 2006  event2
crw------- 1 root root 13, 67 30. Aug 2006  event3
crw------- 1 root root 13, 68 30. Aug 10:43 event4
crw-r--r-- 1 root root 13, 63 30. Aug 2006  mice
crw-r--r-- 1 root root 13, 32 30. Aug 2006  mouse0
crw-r--r-- 1 root root 13, 33 30. Aug 2006  mouse1
crw-r--r-- 1 root root 13, 34 30. Aug 10:43 mouse2
lrwxrwxrwx 1 root root      6 30. Aug 11:09 touchpad -> event2
lrwxrwxrwx 1 root root      6 30. Aug 11:18 trackpoint -> event3

In my xorg.conf I have (quoting only the relevant sections here):

--- /etc/X11/xorg.conf ---

Section "InputDevice"
	Identifier	"Trackpoint"
	Driver		"evdev"
	Option		"Device"	"/dev/input/trackpoint"
	Option		"EmulateWheel" "on"
	Option		"EmulateWheelButton" "2"
	Option		"EmulateWheelTimeout" "200"
	Option		"XAxisMapping" "6 7"
	Option		"YAxisMapping" "4 5"
EndSection

Section "InputDevice"
	Identifier	"Touchpad"
	Driver		"synaptics"
	Option		"device"	"/dev/input/touchpad"
EndSection

Section "InputDevice"
	Identifier	"BTMouse"
	Driver		"evdev"
	Option		"device"	"/dev/input/bt_mouse"
	Option		"Emulate3Buttons"
EndSection

Section "ServerLayout"
	Identifier	"LCD only"
	Screen		0 "LCD" 0 0
	InputDevice	"Touchpad"	"CorePointer"
	InputDevice	"Trackpoint"	"AlwaysCore"
	InputDevice	"BTMouse"	"AlwaysCore"
	InputDevice	"Keyboard"	"CoreKeyboard"
EndSection


When I start X, only the touchpad works, the trackpoint and the bluetooth mouse don't and I don't know why. If I change the device name for the trackpoint from 

Option "Device" "/dev/input/trackpoint"

to 

Option "Device" "/dev/input/event3"

then it works! So, what is the difference between /dev/input/event3 and /dev/input/trackpoint which is a symlink to /dev/input/event3 ?

Any ideas?
Thank you,
Andreas Stemmer