(In reply to comment #38)
> Attachment 102081 [details] fixes the "hard lockup with small vertical blue
> stripes" issue, when applied to 3.15.4, and AFAICS dpm works fine.
> 
> The new problem is that I get kernel panic after a few hours if dpm is
> enabled. With the good old profile method the system is stable.

Could you test with latest kernel 3.16 RC (the patch is already included)? I
have been running kernel 3.16-RC4 with this patch for Cayman and I don't get
any lockups anymore. I've been running my system for a few days (games, movies
and so on) without problem.