A conflict between X and radeonfb can cause system memory corruption
when switching console from X (note that this is not realted to the
recent radeonfb patches, the problem has been there forever as far as I
can tell).

This patch works around it in radeonfb by making sure the "offsets"
register that driver the memory mapping of the accel engine are always
properly set before every accel op. A better fix should be done in fbcon
ultimately.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>