Comment 44 for bug 478761

Martyn Russell (martyn-lanedo) wrote :

I have a Brother MFC-7320 and I was getting this this afternoon:

$ scanimage -t
scanimage: open of device brother3:bus3;dev1 failed: Invalid argument

Using strace, I also saw the USBDEVFS_CONTROL error being reported up the stack from the ioctl call.

What fixed this for me was adding my username to the group "lp". I also Added to /lib/udev/rules.d/40-libsane.rules

  MODE="0664", GROUP="lp"

So the final line looks like:

  ATTRS{idVendor}=="04f9", MODE="0664", GROUP="lp", ENV{libsane_matched}="yes"

Note, you may have to:

a) turn off the printer
b) sudo service udev restart
c) log out and log back in (for new group permissions to take effect)
d) turn printer on

Hope this helps.