From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] libata: add support for ATA_16 commands to ATAPI
 devices
Date: Wed, 3 Jan 2007 11:34:15 +0000
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To: Mark Lord <liml@rtr.ca>
Cc: Jeff Garzik <jeff@garzik.org>, Linux IDE <linux-ide@vger.kernel.org>, Tejun Heo <htejun@gmail.com>

> > For 16 byte commands via SG_IO you know the command is 16 bytes long as
> > the command length is passed in hdr->cmd_len which becomes rq->cmd_len.
> > Is that not sufficient to avoid this ATA_16 test if you pass it on to the
> > required functions ?
> 
> No.  The SCSI code calculates the expected cmd_len based on the opcode it sees,
> and makes exceptions only for the vendor-specific command blocks,
> which ATA_16 is *not* part of.

I know it currently does this, the more important question for the ATA
side is - should it ?