(In reply to comment #11)
> Is ULV standing for Ultra-low voltage? If so, isn't this option something
> meant to be applied on APU only?

Mmm don't know. 
Haven't digged more, but my GPU (R7-265) is running hotter than before, always
around 39°-40° (even without any running application).
With the kernel in debian sid, 3.16.X, I can see low temperatures in idle.

I'm unable to trigger this warning booting up with radeon.dpm=0, so I think is
something related to power management.