From owner-svn-src-head@FreeBSD.ORG Sun Oct 24 17:55:20 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5820A1065673; Sun, 24 Oct 2010 17:55:20 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 856868FC18; Sun, 24 Oct 2010 17:55:18 +0000 (UTC) Received: by fxm17 with SMTP id 17so2207419fxm.13 for ; Sun, 24 Oct 2010 10:55:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=olUGFM9qA7DvZC9LUgMAyNO4slEoSGQ7lx5cQzVvYZE=; b=J/2gu0k+MCc3WJW7i+ocbYfbC78oqMl9pXJkxD7bQOMXboA52DzJwBwO+3zUCdcMmZ VcHTMbifpSxDA/CbnE1pKSaHRblwciUYGCqMH7jmmwQ1oyZhoI9YVGgnMY6/L71awnLM 6HqGdcsWIb4Iolwn+xHlTpKt+zPMC2Z4qeSEM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=NM7/Xzcd0U9dzAMdXrTnpCyvHuGQt7UdGr5Hs611hSgeiCQ5q+9fdaRRobQD9BJX96 Ub6hzF+Ma5R0awKK04wuJEnW3ZtIRd5Y+Duo6yGK7u29wY+a7mpxj2zHV4SF7xDczlTV +8F3OpziE70kXmKtpXMzZGLWxI1ivy9RTWfrM= Received: by 10.102.244.13 with SMTP id r13mr798456muh.14.1287942918087; Sun, 24 Oct 2010 10:55:18 -0700 (PDT) Received: from mavbook2.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id p2sm2458753fak.22.2010.10.24.10.55.15 (version=SSLv3 cipher=RC4-MD5); Sun, 24 Oct 2010 10:55:17 -0700 (PDT) Sender: Alexander Motin Message-ID: <4CC47301.9020609@FreeBSD.org> Date: Sun, 24 Oct 2010 20:55:13 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20091212) MIME-Version: 1.0 To: Garrett Cooper References: <201010241631.o9OGVw1C033817@svn.freebsd.org> <201010241735.32876.bruce@cran.org.uk> <4CC466D5.6080306@FreeBSD.org> In-Reply-To: X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Cc: Bruce Cran , svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r214279 - in head: share/man/man4 sys/cam sys/cam/ata sys/kern X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Oct 2010 17:55:20 -0000 Garrett Cooper wrote: > On Sun, Oct 24, 2010 at 10:03 AM, Alexander Motin wrote: >> Bruce Cran wrote: >>> On Sunday 24 October 2010 17:31:58 Bruce Cran wrote: >>> >>>> Log: >>>> Mostly revert r203420, and add similar functionality into ada(4) since >>>> the existing code caused problems with some SCSI controllers. >> Proper way would be IMHO to fix polling in aac driver. >> >>>> A new sysctl kern.cam.ada.spindown_shutdown has been added that controls >>>> whether or not to spin-down disks when shutting down. >>>> Spinning down the disks unloads/parks the heads - this is >>>> much better than removing power when the disk is still >>>> spinning because otherwise an Emergency Unload occurs which may cause >>>> damage to the actuator. >>> The FLUSH CACHE + STANDBY IMMEDIATE commands are issued (instead of just >>> SLEEP) following the procedure documented in Fujitsu's MHW series product >>> documentation under section 1.10.1, "Recommended power-off sequence". >> Not instead of "just SLEEP", but instead of FLUSH CACHE (by respective >> peripheral driver) + SLEEP (by xpt). It should probably be the same. >> >> Just for the note, SCSI specification states that STOP automatically >> implies FLUSH CACHE. ATA - doesn't. > > I could be wrong, but I think the ANSI ATA<->SCSI spec states > otherwise (taken from ANSI INCITS 431-2007 page 62 -- see steps 1-4): > > 9.11.3 START STOP UNIT START bit LOEJ bit combinations > The SATL shall perform the actions shown in table 40 in response to a > START STOP UNIT command. > Table 40 — Definition of START and LOEJ bits in the START STOP UNIT CDB > START LOEJ Definition > 0 0 The SATL shall: > 1) If the IMMED bit is set to one, then return GOOD status; > 2) Issue an ATA flush command (see 3.1.11) to the ATA device; > 3) If the ATA flush command completes with any error, then process ending status > according to the IMMED bit (see 9.11.2) with the additional sense code set to > COMMAND SEQUENCE ERROR; > 4) If the ATA flush command completes without error, then issue an ATA STANDBY > IMMEDIATE command to the ATA Sector Count set to zero; > 5) If the ATA STANDBY IMMEDIATE command completes with any error, then > process ending status according to the IMMED bit (see 9.11.2) with the > additional > sense code set to COMMAND SEQUENCE ERROR; and > 6) If the ATA STANDBY IMMEDIATE command completes without error and the > IMMED bit is set to zero, then return GOOD status (see 9.11.2) a. > > Not sure about the ATA spec standalone... might be present in the ATA8 spec. As I understand, this just confirms what I have said: SCSI STOP == ATA FLUSH CACHE + STANDBY IMMEDIATE. So SCSI STOP implies flush, while ATA STANDBY IMMEDIATE doesn't. -- Alexander Motin