From: Tejun Heo <tj@kernel.org>
To: Mark Lord <kernel@start.ca>
Cc: vinayak.kale@gmail.com, linux-ide@vger.kernel.org,
linux-kernel@vger.kernel.org, sumit.g.gupta@seagate.com,
Vinayak Kale <vinayak.kale@seagate.com>
Subject: Re: [PATCH v2] libata: add support for NCQ commands for SG interface
Date: Mon, 16 Nov 2015 10:31:33 -0500 [thread overview]
Message-ID: <20151116153133.GA18894@mtj.duckdns.org> (raw)
In-Reply-To: <5649DE67.7080509@start.ca>
On Mon, Nov 16, 2015 at 08:47:19AM -0500, Mark Lord wrote:
> On 15-10-27 01:49 AM, vinayak.kale@gmail.com wrote:
> >From: Vinayak Kale <vinayak.kale@seagate.com>
> >
> >This patch is needed to make NCQ commands with FPDMA protocol value
> >(eg READ/WRITE FPDMA) work over SCSI Generic (SG) interface.
> ..
> >+ /* For NCQ commands with FPDMA protocol, copy the tag value */
> >+ if (tf->protocol == ATA_PROT_NCQ)
> >+ tf->nsect = qc->tag << 3;
> >+
>
>
> What prevents the qc-tag value here from conflicting with in-flight I/O
> using the exact same qc-tag ??
The SG command doesn't set the tag, it's being set from an allocated
qc which can't otherwise be in-flight.
Thanks.
--
tejun
prev parent reply other threads:[~2015-11-16 15:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-27 5:49 [PATCH v2] libata: add support for NCQ commands for SG interface vinayak.kale
2015-10-27 6:16 ` Tejun Heo
2015-10-27 6:37 ` Vinayak Kale
2015-11-16 13:47 ` Mark Lord
2015-11-16 15:31 ` Tejun Heo [this message]
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