[Intel-gfx] [PATCH] allocate MCHBAR space & enable if necessary

[Jesse Barnes]

On Tuesday, January 27, 2009 4:52 pm Jesse Barnes wrote:
> On Tuesday, January 27, 2009 3:27 pm 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.  I've only tested it on 915 so far, but would appreciate wider
> > testing.
> >
> > In combination with the pre-965 tiling patches I posted earlier (which
> > Eric is now integrating), you should see a big performance improvement if
> > you have an affected machine.
>
> Here's an updated version that remembers whether the BAR should be disabled
> again or not.

Forgot to mention that the ACPI code came from arch/x86/pci/mmconfig-shared.c 
so it's GPL. :/  But I guess the BSD code will have to be different here 
anyway, so maybe that's not a problem as long as we note which stuff is GPL.

-- 
Jesse Barnes, Intel Open Source Technology Center