Debugging how udev create devices
To make udev outputs debugging information when creating devices, go to the
/etc/udev/udev.conf and set
udev_log = "debug" as told in this page:
Novell website page
It says that the log will be available in /var/log/messages, but I couldn't find it...
Rules for udev
Sometimes, general configurations in udev are not useful. You can easily
override these rules by creating your own rule. Just add a file to the
/etc/udev/rules.d directory. All files in this directory are concatenatted
in lexical order and validatted.
So, imagine that your application creates the joystick device in
[0-9] range means it can append any numeric
digit to the "js" name. Your application doesn't know where the device was
created. You can make a udev rule that creates the /dev/input/joystick symlink
to the joystick device:
SUBSYSTEM=="input", KERNEL=="js*", SYMLINK+="input/joystick"
See the writing udev rules article, by Daniel Drake, and udev man page for more information.
writing udev rules
udev man page