Message-ID: <4729A23E.7000601@garzik.org>
Date: Thu, 01 Nov 2007 05:54:06 -0400
From: Jeff Garzik <jeff@garzik.org>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: linux-ide@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] libata ATAPI transfer size cleanups
References: <20071101090733.GA9258@havoc.gtf.org> <20071101094344.6eb9d8bc@the-village.bc.nu>
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Alan Cox wrote:
> On Thu, 1 Nov 2007 05:07:33 -0400
> Jeff Garzik <jeff@garzik.org> wrote:
> 
>> This is purely for comment and testing, not for merging (yet?).
>>
>> A common recipe in several vendor drivers (either GPL'd, or I have NDA'd
>> access to use them as a documentation-like reference) for ATAPI was
>> slightly different from ours.  This recipe can be found in
>> atapi_tf_xfer_size(), and it's slightly different from Alan's.
> 
> Looks mostly good. Might cause breakage on one or two controllers by
> setting lbam/lbah to 0 for DMA but we can test that and find out.

DMA always zeroed lbam/lbah thanks to memset(), my patch merely made it 
explicit.


> Note however - the scheme in use now has been tested for over ten years
> in drivers/ide. The scheme below has not...

See my other email just posted, differences and errata abound :)

	Jeff


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