From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jens Axboe <jens.axboe@oracle.com>
Subject: Re: [PATCH 2/2] libata: turn off NCQ if queue depth is adjusted to 1
Date: Thu, 5 Oct 2006 11:08:22 +0200
Message-ID: <20061005090820.GM5170@kernel.dk>
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To: saeed bishara <saeed.bishara@gmail.com>
Cc: Tejun Heo <htejun@gmail.com>, Ric Wheeler <ric@emc.com>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Jeff Garzik <jgarzik@pobox.com>, linux-ide@vger.kernel.org

On Wed, Oct 04 2006, Jens Axboe wrote:
> On Wed, Oct 04 2006, saeed bishara wrote:
> > the NCQ commands contain the FUA (force unit access) field
> > (mandatory), so disabling the NCQ will waste this feature.
> > I don't know how much ans when this feature is usuable, but someday it
> > can be usefull.
> 
> It's already useful, for io barriers. Yet another reason why the
> distinction between depth == 1 and NCQ needs to available.

Ehm, I completely missed the bigger picture - non-ncq has FUA available
too. So NCQ or not has no bearing on FUA functionality.

-- 
Jens Axboe