Date: Wed, 6 Aug 2008 15:13:02 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Matthew Wilcox <matthew@wil.cx>
Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, jgarzik@pobox.com,
       Matt_Domsch@dell.com, Matthew Wilcox <willy@linux.intel.com>
Subject: Re: [PATCH] ata: Add support for Long Logical Sectors and Long
 Physical Sectors
Message-ID: <20080806151302.1d282747@lxorguk.ukuu.org.uk>
In-Reply-To: <20080806131109.GH2055@parisc-linux.org>
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	<20080806131109.GH2055@parisc-linux.org>
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> Obviously it is going to change per command -- because different
> commands have different sizes.  I was thinking that we could call the
> driver to see if it can handle a particular sector size right after we
> get the IDENTIFY data.  

The drivers need to know if you are going to be using odd sizes regularly
so they can pick between

	-	I do this fine who cares (most chips)
	-	Er uh wtf its not 512 byts (some chip state machines)
	-	FIFO off (performance hit) for this disk
	-	FIFO managed for the odd command thats a funny size
	-	Various other levels of software managed controller
		thumping

It's not a passive thing and we'd want to do it post identify on the
drive pair as it'll often need per channel decisions (eg on FIFO)

Alan
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