Subject: Re: Mystery packet killing tg3

From: Peter Buckingham <[email-masked]>
Date: Wed, 04 May 2005 11:44:53 -0700

Andi Kleen wrote:
> "David S. Miller" <[email-masked]> writes:
> 
>>This usually means that there is some DMA corruption.
>>For example, some bug in the x86_64 IOMMU code or similar
>>causes a bogus DMA address to be fed to the tg3 or even
>>worse a DMA mapping is unmapped before tg3 is actually
>>done with it.
> 
> 
> IOMMU code on x86-64 should be never active unless Stephen
> used IOMMU_DEBUG or iommu=force.  THat is because the tg3
> is a 64bit capable device and should always use bypass.

how is this detected? we have a board that is using a 32bit e1000 and we 
have to use iommu=force otherwise it doesn't do the right thing with > 
4GB of RAM.

peter