Comment 23 for bug 420015

Truthiswithin, Thanks.

Now we know what to do:

1. Remove/blacklist "usblp" kernel module (for example by adding a file /etc/modprobe.d/blacklist-cups.conf to the cups package and also "rmmod usblp" to the pre- or post-install script of cups)

2. Add udev rules to make the /dev/bus/usb/*/* files corresponding to printers have the permissions 664 and group ownership "lp".

3. Change AppArmor configuration to let the "usb" CUPS backend (or CUPS in general) have read and write access to the /dev/bus/usb/*/* files.

With all this done USB printers will work out-of-the-box again.