https://bugs.freedesktop.org/show_bug.cgi?id=46274
--- Comment #3 from Florian Mickler florian@mickler.org 2012-02-27 14:29:59 PST --- A patch referencing this bug report has been merged in Linux v3.3-rc5:
commit f0d14daa6906070ca044b86f483fdde7d81f5294 Author: Michel Dänzer michel.daenzer@amd.com Date: Tue Feb 21 17:39:15 2012 +0100
drm/radeon: Only create additional ring debugfs files on Cayman or newer.