From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Lord <liml@rtr.ca>
Subject: Re: ops->qc_defer not invoked on ata_exec_internal_sg() paths ?
Date: Tue, 26 Feb 2008 10:47:42 -0500
Message-ID: <47C4349E.5010802@rtr.ca>
References: <47C35B6B.8000406@rtr.ca> <20080226123209.7ca9eed4@core>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tejun Heo <htejun@gmail.com>, IDE/ATA development list <linux-ide@vger.kernel.org>

Alan Cox wrote:
> On Mon, 25 Feb 2008 19:20:59 -0500
> Mark Lord <liml@rtr.ca> wrote:
> 
>> The optional .qc_defer() methods don't seem to be called
>> on the ata_exec_internal_sg() path.
>>
>> At present, this is probably okay.  But in the future,
>> as we add functionality for link power management
>> and hotplug polling, this could be a problem.
> 
> It becomes a problem for me certainly if we ever issue anything via
> exec_internal_sg while another command may be outstanding anywhere on the
> same *host*. Right now its ok.
..

Yeah, for serializing a pair of ATA channels on the same host chip.

-ml