Wacom Graphire3 tablet: need to change event device number every boot

Q I have a strange problem with my Wacom Graphire3 tablet: I have to change events in my xorg.conf every time I turn on my machine. I'm currently on Fedora 6 with Gnome and my xorg.conf is exactly the same as it was when I was using Fedora 5 with Gnome and the same hardware setup. The tablet worked perfectly at that time. I've tried searching Google with no success, so I don't have a clue what is happening. Any pointers even to help me understand the problem would be great.

A I take it you mean you have to change the number of the event device. Your enclosed xorg.conf contains

Option "Device" "/dev/input/event2"

and you have to change the number. This is because input devices are numbered in the order they are detected, and something is changing the order each time you boot - maybe another device that is only sometimes connected, such as a memory stick or scanner. The solution is to get udev, the device manager, to assign a persistent name to your tablet, one that it will always have irrespective of detection order. This is done by writing a udev rule. You first have to see how the system identifies the device with

udevinfo -a -p /sys/class/input/event2 | less

When run on my Aiptek tablet, the third block of output contains:

SUBSYSTEMS=="usb"
DRIVERS=="aiptek"
ATTRS{vendor}=="AIPTEK"

This is plenty to uniquely identify the device; you should see something similar for your Wacom tablet. To turn this into a udev rule, open a terminal, use su to become root and use your favourite editor to edit /etc/udev/rules.d/10-local.rules (create the file if it does not exist). Now, please do not be tempted to add the rule to an existing rules file, as it may be overwritten when udev is updated 10-local.rules is the correct place for your own rules. Now add a line like this, but using the values from when you ran the udevinfo command:

SUBSYSTEMS=="usb", DRIVERS=="aiptek",
ATTRS{vendor}=="AIPTEK", SYMLINK:="input/tablet"

You'll see it's just the attributes that identify the device, separated by commas, followed by a SYMLINK setting. Note that the attributes are followed by ==, indicating a comparison, whereas the final item uses := because it is assigning a value. Your device will still be created as /dev/input/eventN but it will be linked from /dev/input/tablet, whatever the value of N - running ls -l /dev/input will confirm this. Now you can use /dev/input/tablet in xorg.conf and your tablet should always work.

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