From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758155AbXGDQpX (ORCPT ); Wed, 4 Jul 2007 12:45:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757307AbXGDQon (ORCPT ); Wed, 4 Jul 2007 12:44:43 -0400 Received: from noname.neutralserver.com ([70.84.186.210]:26473 "EHLO noname.neutralserver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757116AbXGDQoj (ORCPT ); Wed, 4 Jul 2007 12:44:39 -0400 X-Greylist: delayed 3627 seconds by postgrey-1.27 at vger.kernel.org; Wed, 04 Jul 2007 12:44:38 EDT Date: Wed, 4 Jul 2007 19:44:26 +0300 From: Dan Aloni To: Michael Tokarev Cc: Kernel Mailing List , linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: Some NCQ numbers... Message-ID: <20070704164426.GA8061@localdomain> References: <468392CE.6010206@msgid.tls.msk.ru> <20070704154405.GA27166@localdomain> <468BC81F.7090102@msgid.tls.msk.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <468BC81F.7090102@msgid.tls.msk.ru> User-Agent: Mutt/1.5.13 (2006-08-11) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - noname.neutralserver.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - monatomic.org X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 04, 2007 at 08:17:35PM +0400, Michael Tokarev wrote: > Dan Aloni wrote: > > On Thu, Jun 28, 2007 at 02:51:58PM +0400, Michael Tokarev wrote: > >> [..] > >> Test machine was using MPTSAS driver for the following card: > >> SCSI storage controller: LSI Logic / Symbios Logic SAS1064E PCI-Express Fusion-MPT SAS (rev 02) > >> > >> Pretty similar results were obtained on an AHCI controller: > >> SATA controller: Intel Corporation 82801GR/GH (ICH7 Family) Serial ATA Storage Controller AHCI (rev 01) > >> on another machines. > > > > Are you sure that NCQ was enabled between the controller and drive? > > Did you verify this? I know about some versions that disable NCQ > > support internally in their firmware (something to do with bugs in > > error handling). > > The next obvious question is: how to check/verify this? On the lowest level, it's possible using a protocol analyzer. If you don't have one, you need to be familiar with the controller's driver or its firmware. If the driver is based on libata, I think it's possible to get this information easier. Otherwise, such as in the case of mptsas, it can be completely hidden by the firmware. -- Dan Aloni XIV LTD, http://www.xivstorage.com da-x (at) monatomic.org, dan (at) xiv.co.il