Re: [coreboot] Crazy Intel graphics mtrr

> On Wed, Apr 16, 2008 at 5:03 PM,   wrote:
> > Hello,
> >  I am noticing some X problems (slow, crashes once and a while) on the RCA
>
> RM4100. I think this is related to the crazy way coreboot setup the mtrr. For 
> some reason when the Intel onboard graphics are enabled, coreboot sets up this 
> crazy looking mtrr. I don't think they should all be write-back? Isn't 
> write-combining faster for graphics? Does it need to have a uncachable area?
> >
>
> that is normal.
> > reg00: base=0x00000000 (   0MB), size=  64MB: write-back, count=1
> >  reg01: base=0x04000000 (  64MB), size=  32MB: write-back, count=1
> >  reg02: base=0x06000000 (  96MB), size=  16MB: write-back, count=1
> >  reg03: base=0x07000000 ( 112MB), size=   8MB: write-back, count=1
>
> ==
> > reg00: base=0x07800000 ( 120MB), size=   8MB: uncachable, count=1
> >  reg01: base=0x00000000 (   0MB), size= 128MB: write-back, count=1
>
> and old kernel like previous one
> 64+32+16+8 == (128 - 8)
>
> YH

Hmm, so it all adds up but, what is the need for 3 different mtrr's instead of one? Also, what about this:
> > I don't think they should all be write-back? Isn't 
> > write-combining faster for graphics? Does it need to have a uncachable area?