From owner-freebsd-current@FreeBSD.ORG  Wed Nov 18 17:14:47 2009
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from hub.freebsd.org (localhost [127.0.0.1])
	by hub.freebsd.org (Postfix) with ESMTP id B0FDF1065672;
	Wed, 18 Nov 2009 17:14:46 +0000 (UTC)
	(envelope-from nork@FreeBSD.org)
Date: Thu, 19 Nov 2009 02:14:40 +0900
From: Norikatsu Shigemura <nork@FreeBSD.org>
To: Alexander Motin <mav@freebsd.org>
Message-Id: <20091119021440.560884b2.nork@FreeBSD.org>
In-Reply-To: <4B042304.8060807@FreeBSD.org>
References: <20091119004651.7432a6e4.nork@FreeBSD.org>
	<4B042304.8060807@FreeBSD.org>
X-Mailer: Sylpheed 2.7.1 (GTK+ 2.16.6; i386-portbld-freebsd8.0)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: freebsd-current@freebsd.org, Norikatsu Shigemura <nork@freebsd.org>
Subject: Re: How do I use NCQ of Intel X25-E(SSD) on ahci(4)?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Nov 2009 17:14:47 -0000

Hi Alexander.

On Wed, 18 Nov 2009 18:38:28 +0200
Alexander Motin <mav@freebsd.org> wrote:
> > Native Command Queuing (NCQ)   yes              30/0x1E
> 
> Here is the reason                                ^^^
> This drive support less tags (31) then your AHCI controller does (32).
> Support for such case is not implemented yet. As temporary solution you
> may limit controller to use only 31 tag, then NCQ will be used. All you
> need is to go to ahci.c and change line
> ch->numslots = ...;
> to
> ch->numslots = min(31, ...);

	Oops, OK!  I confirmed following patch:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--- sys/dev/ahci/ahci.c.orig    2009-11-17 22:25:07.474418000 +0900
+++ sys/dev/ahci/ahci.c 2009-11-19 02:00:22.193688908 +0900
@@ -779,7 +779,7 @@
 	ch->caps = ctlr->caps;
 	ch->caps2 = ctlr->caps2;
 	ch->quirks = ctlr->quirks;
-	ch->numslots = ((ch->caps & AHCI_CAP_NCS) >> AHCI_CAP_NCS_SHIFT) + 1,
+	ch->numslots = min(31, ((ch->caps & AHCI_CAP_NCS) >> AHCI_CAP_NCS_SHIFT) + 1),
 	mtx_init(&ch->mtx, "AHCI channel lock", NULL, MTX_DEF);
 	resource_int_value(device_get_name(dev),
 	    device_get_unit(dev), "pm_level", &ch->pm_level);
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

	ahci(4) can use NCQ of X25-E.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <SSDSA2SH064G1GC INTEL 045C8790> ATA/ATAPI-7 SATA 2.x device
ada0: 300.000MB/s transfers
ada0: Command Queueing enabled
ada0: 61057MB (125045424 512 byte sectors: 16H 63S/T 16383C)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# camcontrol tags ada0
(pass0:ahcich0:0:0:0): device openings: 31
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

	Thank you!