From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 9/9] tcm_qla2xxx: Add special case for COMPARE_AND_WRITE
 data_direction
Date: Tue, 20 Aug 2013 23:37:02 -0700
Message-ID: <20130821063702.GI25506@infradead.org>
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To: "Nicholas A. Bellinger" <nab@daterainc.com>
Cc: target-devel <target-devel@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>, linux-scsi <linux-scsi@vger.kernel.org>, Christoph Hellwig <hch@lst.de>, Hannes Reinecke <hare@suse.de>, Martin Petersen <martin.petersen@oracle.com>, Chris Mason <chris.mason@fusionio.com>, James Bottomley <JBottomley@Parallels.com>, Nicholas Bellinger <nab@linux-iscsi.org>, Giridhar Malavali <giridhar.malavali@qlogic.com>, Chad Dupuis <chad.dupuis@qlogic.com>
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On Tue, Aug 20, 2013 at 08:08:00PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@daterainc.com>
> 
> Add a special case for COMPARE_AND_WRITE for the reverse data direction
> mapping used for pci_map_sg() + friends.

A low level driver is an even worse place to hardcode a specific cdb
opcode.  As written before this should be done by a flag on the command.

Also it might make sense to lift this helper to get a dma direction from
a command into common code.