https://bugs.freedesktop.org/show_bug.cgi?id=10471

--- Comment #2 from Chris Rankin rankincj@googlemail.com 2010-07-01 12:55:51 PDT --- [patch 079/149] drm/radeon: r100/r200 ums: block ability for userspace app to trash 0 page and beyond

http://lkml.indiana.edu/hypermail/linux/kernel/1007.0/00405.html

Hmm, "badness" affecting R200 cards under UMS. I wonder...