Date: Sun, 20 Jun 2004 16:50:42 +0100
From: Ian Molton <spyro@f2s.com>
To: James Bottomley <James.Bottomley@SteelEye.com>
Cc: rmk+lkml@arm.linux.org.uk, david-b@pacbell.net,
       linux-kernel@vger.kernel.org, greg@kroah.com, tony@atomide.com,
       jamey.hicks@hp.com, joshua@joshuawise.com
Subject: Re: DMA API issues
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On 20 Jun 2004 08:37:58 -0500
James Bottomley <James.Bottomley@SteelEye.com> wrote:

> 
> There's no architecture currently that can't use the DMA API.
> 
> The modification you propose, to make on chip memory visible as normal
> memory can't be done on the IBM iserie, AS/400 as I said in the the
> email you quote:

Those two statements are contradictory. clearly the iseries cant use the
DMA API *now* so I dont see how that makes any difference. We're talking
about adding propper support for *addresssable* memory mapped devices
with limited size DMA-able windows to the DMA API, not adding support
for a whole new weird way of talking to devices. These devices work the
same way as all the other devices that use the DMA API but are simply
restricted in the range of addresses they can DMA from. they require no
special 'accessors'.

iseries cant work the usual way now and wont with these modifications -
so nothing is made worse.
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