@Mihai I'm using dpm since years on my Mobility 3470 and I only experience
random freezes very rarely. The only thing that's really annoying for me is
this:

  https://bugs.freedesktop.org/show_bug.cgi?id=94933

but it seems that it's not going to be fixed. Actually, all the remaining r6xx
dpm bugs will likely stay here forever, given the shifted focus of AMD
developer towards newer architecture and maybe the lack of hardware for
testing. Many dpm bug report threads end when the opener says he's using dpm,
with developers suddenly ceasing to reply. This sounds a lot like a "WONTFIX"
to me, and I perfectly understand the devs.