Short Nerd Chief

After managing to install Ubuntu 8.04 via Wubi and finagling the wireless into working with ndiswrapper, I decided to actually get some work done, and created some documents in OpenOffice. Time to print, so I tried the easy route first. System >> Administration >> Printing lets you add a printer, and Ubuntu dutifully located the Brother HL-4040CN at its network IP address. It looked for a printer driver, and suggested the driver for the Brother HL-4000. Same family, so it seemed like something worth trying. Bad idea, as it just spit out about 20 blank (but curled) pages.

Brother’s website has instructions for installing drivers in Linux, however. It’s basically a three-step process:

• install the LPR Printer Driver
• install the CUPS wrapper driver
• add the printer

The drivers are *.deb files, which you can double-click in Nautilus or install via the terminal. Once you’ve installed the drivers, you can use the add printer dialog or follow Brother’s instructions. I tried Brother’s instructions, but they didn’t work, as they suggest using “lpd://xx.xx.xx.xx/binary_p1″ as the Device URI, where I actually needed to use socket://xx.xx.xx.xx, which is what the Ubuntu printer dialog suggested.

After clearing that hurdle, it was time for a test page, but it didn’t work. Instead I got this error message:

Unable to start filter “/usr/Brother/Printer/hl4040cn/cupswrapper/brlpdwrapper”

It was unclear why the system wasn’t letting me access the printer files. Trying to change the file permissions had no effect. Luckily a forum post had the answer. Go to a terminal and issue this command:

sudo aa-complain cupsd

The problem appears to be a conflict between the third-party printer driver and AppArmor, which controls application access to system files. Putting AppArmor into complain mode for CUPS means that it will write to a log file but not prevent file access. Printing works great now.