https://bugs.freedesktop.org/show_bug.cgi?id=82201
--- Comment #41 from Sebastian Parborg darkdefende@gmail.com --- For me, it first stated happening when I updated mesa. But now it seems to happen at random.
BTW I have managed to get the GPU to reclock again by booting with fglrx and running Unigine Heaven till I hear the fans spin up. After I then reboot to radeon I have got it to reclock again. This combo has worked for me three of three times now.
At first I just thought that simply bootin with fglrx solved it. But as that didn't work 100% of the time, I thought that perhaps simply booting with it was not enough.
However the test pool size is quite small so I might just have gotten lucky so far with the Heaven method.
Can you check if you get the same result, but with windows?