https://bugzilla.kernel.org/show_bug.cgi?id=22022
--- Comment #28 from Aaron Lu aaron.lu@intel.com 2013-04-08 07:20:40 --- Hi Jonathan,
Rolf's comment seems suggest radeon driver is the problem: https://bugs.freedesktop.org/show_bug.cgi?id=43278#c18
If this is the case, then there is not much we can do in PM side.
dri-devel@lists.freedesktop.org