From: Andi Kleen <ak@suse.de>
To: Robert Hancock <hancockr@shaw.ca>
Subject: Re: X86_64 + VIA + 4g problems
Date: Mon, 2 Jan 2006 21:39:29 +0100
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On Monday 02 January 2006 21:15, Robert Hancock wrote:

> I'm not sure if this would be an issue with Linux. I would suspect that 
> it could be, if there are indeed such buses that can't support DAC.. In 
> this case the right thing to do would be to reject requests for DMA 
> masks larger than 4GB for devices located on such a bus.

Well, from the original messages in this thread which you so shamelessly
hijacked it is possible VIA PCI bridges might have this problem. If yes
it can be handled in the PCI-DMA API by disallowing DAC for devices
behind such bridges. But before taking such drastic action we need
first need more testing results.

-Andi
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