tree 766c8349ac17cf3066c352b50d4359ad33212362
parent 9021f284e9eaff1ed1d3e6bab7c90e3712201ac2
author Daniel Vetter <daniel.vetter@ffwll.ch> 1332747942 +0200
committer Daniel Vetter <daniel.vetter@ffwll.ch> 1332846924 +0200

drm/i915: clear the entire gtt when using gem

We've lost our guard page somewhere in the gtt rewrite, this patch
here will restore it.

Exercised by i-g-t/tests/gem_cs_prefetch.

v2: Substract the guard page from the range we're supposed to manage
with gem. Suggested by Chris Wilson to increase the odds of old ums +
gem userspace not blowing up. To compensate for the loss of a page,
don't substract the guard page in the modeset init code any longer.

Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44748
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>