This reverts the series of commits
67dbb4ea33281ab031a847807ce381
that changed the GART VM start offset. It fixed some machines, but
seems to continually interact badly with some X versions.
Quoth Ben Herrenschmidt:
"So I think at this point, the best is that we keep the old bogus code
that at least is consistent with the bug in the server. I'm working on a
big patch to X that reworks the memory map stuff completely and fixes
those issues on the server side, I'll do a DRM patch matching this X fix
as well so that the memory map is only ever set in one place and with
what I hope is a correct algorithm..."
Signed-off-by: Linus Torvalds <torvalds@osdl.org>