[Intel-gfx] [PATCH] allocate & enable MCHBAR if needed
chris at chris-wilson.co.uk
Thu Feb 12 12:38:02 CET 2009
On Wed, 2009-02-11 at 17:54 -0800, Jesse Barnes wrote:
> I noticed on my Eee 901 that the i915 DRM driver wasn't reading the MCHBAR reg
> at startup time, and so it would disable tiling. For decent performance,
> especially on an Eee-like platform, tiling is a must. So I put this patch
> together to allocate MCHBAR space and enable it if necessary.
> In combination with the pre-965 tiling patches in the tree now, you should see
> a big performance improvement if you have an affected machine.
> (Note to Eric: don't merge this until someone else confirms it works for them
No joy, I'm afraid. This patch fails to enable tiling on my el cheapo
eee 700. Just to reaffirm with the previous patch I get a performance
boost of around a factor of 20x over this version.
(And /proc/dri/0/i915_gem_fence indeed reports no tiling). I noticed
that wasn't any debugging output; is there anything I can do to help?
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