https://bugzilla.kernel.org/show_bug.cgi?id=63101
--- Comment #12 from Kertesz Laszlo laszlo.kertesz@gmail.com --- (In reply to Alex Deucher from comment #11)
(In reply to Kertesz Laszlo from comment #10)
This issue has to do with the radeon driver, because if i dont append radeon.dpm=1 to the kernel boot options, TF2 launches even with latest 3.12 rc5+ kernel (but it has dismal performance).
If it was dpm specific you should have mentioned that. Make sure your kernel has this patch: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/ ?id=4076a65544e2de310cbf4eaadb13ee15bbfaaf4f
Sorry about that. I have the dpm option there since it appeared, i totally forgot about it - now i started the computer in single user mode which doesnt have that option then i proceeded to runlevel 2. This way i saw this.
I have that patch, i have the linus kernel cloned from git (now at version v3.12-rc5-123-g04919af). I even re cloned it recently.
Also please take a look at bug #62861 - it is related to the dpm code too.