https://bugs.freedesktop.org/show_bug.cgi?id=36602
--- Comment #16 from Pierre-Eric Pelloux-Prayer pelloux@gmail.com 2011-08-05 08:49:46 PDT --- (In reply to comment #15)
I'm applying the patches to linux 3.0 but maybe that's too old already?
Your backtrace show this: "num_tile_pipes = 0" which is wrong. This value is asked by r600g to kernel using 'RADEON_INFO_NUM_TILE_PIPES' request.
Linux 3.0 kernel have all in place to handle this request (in radeon_kms.c), so num_tile_pipes definitely shouldn't be null.
Did you check if your kernel log (or Xorg ?) contain something interesting ?