Re: PCI-DMA: high address but no IOMMU

From: Nishanth Aravamudan
Date: Sun Oct 30 2005 - 09:31:59 EST


On 27.10.2005 [18:59:00 -0700], Nishanth Aravamudan wrote:
> On 27.10.2005 [15:39:20 -0700], Michael Madore wrote:
> > On 28 Oct 2005 00:16:51 +0200, Andi Kleen <ak@xxxxxxx> wro> >
> > > > Checking aperture...
> > > > CPU 0: aperture @ 8000000 size 32 MB
> > > > Aperture from northbridge cpu 0 too small (32 MB)
> > > > No AGP bridge found
> > > > Your BIOS doesn't leave a aperture memory hole
> > > > Please enable the IOMMU option in the BIOS setup
> > > > This costs you 64 MB of RAM
> > > > Mapping aperture over 65536 KB of RAM @ 8000000
> > > >
> > > > ...
> > > >
> > > > PCI-DMA: Disabling AGP.
> > > > PCI-DMA: aperture base @ 8000000 size 65536 KB
> > > > PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture
> > >
> > > Can you post the full boot log?
> > >
> >
> > Hi Andy,
> >
> > Here is the full boot log from 2.6.14-rc5.
>
> Just as another datapoint, here is mine (ignore the inode issues, they
> are due to a power failure yesterday):

Ah, silly me, I set IOMMU_DEBUG to Y at some point without realizing.
Taking that away removed the issues and I now only get:

[ 0.000000] Checking aperture...
[ 0.000000] CPU 0: aperture @ 4000000 size 32 MB
[ 0.000000] Aperture from northbridge cpu 0 too small (32 MB)
[ 0.000000] No AGP bridge found

...

[ 47.737770] PCI-DMA: Disabling IOMMU.

Which makes a lot more sense.

Sorry for the noise.

Thanks,
Nish
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