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Date: Tue, 21 Nov 2006 20:04:47 +0000
From: Alan <alan@lxorguk.ukuu.org.uk>
To: Andi Kleen <ak@suse.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>, Ray Lee <ray-lk@madrabbit.org>,
       linux-kernel@vger.kernel.org
Subject: Re: Problem with DMA on x86_64 with 3 GB RAM
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> If it did like you're recommending a huge number of drivers
> in the tree wouldn't work anymore (just think about what pci_alloc_consistent
> does) 

There are very few drivers who actually request less than 32bit DMA
and those would (and should) fail or be forced to do their own fallbacks.

Alan