https://bugs.freedesktop.org/show_bug.cgi?id=82201
--- Comment #15 from Kai kai@dev.carbon-project.org --- (In reply to comment #11)
Created attachment 104101 [details] [review] enable dpm=1 debugging even when dpm is not forced
This patch enables the additional dpm debugging output even when it is not explictly set on the command line. Does it help? The only thing I can figure is that the debugging output adds a small delay that may have a positive impact.
You're not going to like this. But setting radeon.dpm=1 must have some other side effect. I booted each configuration represent by attachment 104103 and attachment 104104 two times. The first (104103) is the stack from comment #0 plus the patch from attachment 104101 applied to the kernel, then booted without radeon.dpm=1 (see the dmesg output for the kernel command line). When I start Portal 2 I stay at the numbers reported in comment #0 (ie. at low FPS).
If I boot the stack from comment #0 with the patch from attachment 104101 applied to the kernel and DO set radeon.dpm=1 on the kernel command line (see second dmesg output; 104104), then I get 60 FPS in Portal 2.