Re: [2.6.17.11] strange pcie errors/warnings on Abit KN9-SLI mainboard

Arjan van de Ven
2006-08-28T08:15:09Z

On Mon, 2006-08-28 at 07:55 +0200, Jan De Luyck wrote:
> Hello,
>
> (running 2.6.17.11 vanilla on Debian SID)
>
> I recently acquired a new pc, with an ABIT KN9-SLI mainboard, using an AMD64x2
> AM2 processor.
>
> System boots fine, but I have some messages/errors in the dmesg that I'm worried
> about. Googling around for them didn't really show up much.
>
> First:
>
> Aug 27 15:35:04 whocares kernel: PCI-DMA: Disabling IOMMU.
>
> IOMMU is (as far as I can see) enabled:
> whocares:/var/log# cat /usr/src/build/linux-2.6/.config | grep IOMMU
> CONFIG_GART_IOMMU=y
>
> I can't really determine if this is normal. According to the code it seems that
> this is disabled by default when you don't have AGP? (I'm not a kernel-coder, so
> I may be very wrong on this)

Hi,

unless you have >= 4Gb of ram you don't need an IOMMU (in fact using it
would only cause extra overhead)... so the kernel will not use it in
that case.

Greetings,
Arjan van de Ven