From: Christoph Hellwig <hch@infradead.org>
To: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>,
Webb Scales <webbnh@hp.com>,
James Bottomley <jbottomley@parallels.com>,
linux-scsi@vger.kernel.org
Subject: Re: [PATCH] megaraid_sas: Enable shared tag map
Date: Thu, 2 Oct 2014 02:19:16 -0700 [thread overview]
Message-ID: <20141002091916.GA13227@infradead.org> (raw)
In-Reply-To: <542CF5E8.3030601@suse.de>
On Thu, Oct 02, 2014 at 08:51:20AM +0200, Hannes Reinecke wrote:
>
> I'm afraid it's not _that_ easy.
> SCSI-II tagged queueing has some specific tag values:
>
> #define SIMPLE_QUEUE_TAG 0x20
> #define HEAD_OF_QUEUE_TAG 0x21
> #define ORDERED_QUEUE_TAG 0x22
These are not tag values. These are message codes set in the first byte
of the Queue tag message, the second byte is the actual tag.
> The recommendation here is to use 'scmd->request->tag' whenever
> you want to get to the tag number, and 'scmd->tag' if you have to
> play around with SCSI-II TCQ.
> But if not I would strongly advise to leave 'scmd->tag' alone.
Or kill off scmd->tag.. Let's see how feasible that is.
next prev parent reply other threads:[~2014-10-02 9:19 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-29 11:47 [PATCH] megaraid_sas: Enable shared tag map Hannes Reinecke
2014-09-29 16:52 ` Webb Scales
2014-09-29 17:08 ` James Bottomley
2014-09-30 7:43 ` Christoph Hellwig
2014-09-30 9:08 ` Hannes Reinecke
2014-10-01 18:51 ` Webb Scales
2014-10-01 21:10 ` Christoph Hellwig
2014-10-02 6:51 ` Hannes Reinecke
2014-10-02 9:19 ` Christoph Hellwig [this message]
2014-10-02 9:50 ` Hannes Reinecke
2014-10-02 11:36 ` Christoph Hellwig
2014-10-02 12:00 ` Hannes Reinecke
2014-10-02 14:32 ` Christoph Hellwig
2014-10-02 12:05 ` James Bottomley
2014-10-02 12:14 ` Hannes Reinecke
2014-10-02 13:06 ` James Bottomley
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20141002091916.GA13227@infradead.org \
--to=hch@infradead.org \
--cc=hare@suse.de \
--cc=jbottomley@parallels.com \
--cc=linux-scsi@vger.kernel.org \
--cc=webbnh@hp.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.