https://bugs.freedesktop.org/show_bug.cgi?id=78453
--- Comment #52 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #51)
Unfortunatly with "radeon.test=3" the tty doesnt even appear, and it looks like sshd server is never run, I cant access anything :/
Try booting into a non-X runlevel and then manually loading radeon from the command line.