Using evergreen(cedar) hardware reading from /sys/kernel/debug/dri/0/radeon_ring_cp cause null-pointer dereference with latest linus git(3.3-rc4).
Created attachment 57337 [details] [review]
Only create additional ring info files on Cayman or newer
This patch should not create the additional files at all for your card. I've only been able to compile-test it, does it work for you?
I've tested the fix and submitted it, should make it into 3.3 final.
A patch referencing this bug report has been merged in Linux v3.3-rc5:
Author: Michel DÃ¤nzer <firstname.lastname@example.org>
Date: Tue Feb 21 17:39:15 2012 +0100
drm/radeon: Only create additional ring debugfs files on Cayman or newer.
Resolving per comment #3.