Subject: Re: lack of pciide transfer alignment checking causes crash
To: Daniel Carosone <dan@geek.com.au>
From: Jason Thorpe <thorpej@shagadelic.org>
List: tech-kern
Date: 06/28/2005 19:22:42
On Jun 28, 2005, at 5:10 PM, Daniel Carosone wrote:

> I think Thor has in mind something like this (certainly, I do)
>
> pci0 at mainbus0
> bouncepci0 at pci0
> bouncepci0: using bounce buffers for transfers above 1Gb
> bce0 at bouncepci0

No, the right way to do this is to allow devices to specify their  
constraints more accurately when they create DMA maps (or allowing  
them to allocate new tags and then functionally set some parameters  
in those tags).  A stupid kludge like "bouncepci" is totally  
unnecessary on systems that have an IOMMU, for example.

-- thorpej