https://bugs.freedesktop.org/show_bug.cgi?id=60802
--- Comment #32 from Alex Deucher agd5f@yahoo.com --- Created attachment 75658 --> https://bugs.freedesktop.org/attachment.cgi?id=75658&action=edit align dma commands to 8 dwords
Does this patch help? You might also try it in combination with this patch: http://lists.freedesktop.org/archives/mesa-dev/2013-February/035347.html