From owner-cvs-all@FreeBSD.ORG Tue Jan 31 05:23:00 2006 Return-Path: X-Original-To: cvs-all@freebsd.org Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2C1AA16A420; Tue, 31 Jan 2006 05:23:00 +0000 (GMT) (envelope-from nate@root.org) Received: from www.cryptography.com (li-22.members.linode.com [64.5.53.22]) by mx1.FreeBSD.org (Postfix) with ESMTP id C7C9B43D45; Tue, 31 Jan 2006 05:22:59 +0000 (GMT) (envelope-from nate@root.org) Received: from [10.0.0.53] (adsl-67-119-74-222.dsl.sntc01.pacbell.net [67.119.74.222]) by www.cryptography.com (8.12.8/8.12.8) with ESMTP id k0V5MvEr002952 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 30 Jan 2006 21:22:58 -0800 Message-ID: <43DEF43A.6090804@root.org> Date: Mon, 30 Jan 2006 21:23:06 -0800 From: Nate Lawson User-Agent: Mozilla Thunderbird 1.0.6 (Windows/20050716) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Florent Thoumie References: <20060130202806.DCC7916A4CA@hub.freebsd.org> <200601310133.34152.flz@xbsd.org> <43DEB6C5.8090504@root.org> <200601310251.16946.flz@xbsd.org> In-Reply-To: <200601310251.16946.flz@xbsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Tue, 31 Jan 2006 05:40:10 +0000 Cc: freebsd-scsi@freebsd.org Subject: Re: cvs commit: src/sys/cam/scsi scsi_da.c src/sys/dev/usb umass.c usbdevs X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Jan 2006 05:23:00 -0000 Florent Thoumie wrote: > On Tuesday 31 January 2006 02:00, Nate Lawson wrote: > >>Florent Thoumie wrote: >>>It seems a lot of devices are concerned by the sync cache problem, would >>>it be harmful to just remove this part of the code or could there be a >>>way to detect if the device supports it or not? >> >>Well, it's important to run SYNC_CACHE in shutdown or possibly when >>unmounting a filesystem. Otherwise, data could be lost on boot. >>However, I support adding a USB-specific mechanism that says SYNC_CACHE >>should only be run on shutdown or device_eject, that way devices that >>hang after this command is run would still work at runtime. And SCSI >>devices that support multiple calls to SYNC_CACHE (i.e. most non-USB >>devs) would still work too. >> >>However, the first step is to investigate what windows and Linux do. > > > Linux only sends the SYNCHRONIZE_CACHE command if the WCE (Write Cache Enable) > bit of the disk is set. I can't seem to find something equivalent to this in > our CAM framework. I have no particular SCSI knowledge but I guess I can have > a look at this tomorrow. > > I'm forwarding this to freebsd-scsi@ (keep me CC'ed, as I'm not subscribed to > this list, yet). Hmm, is WCE part of the inquiry response? [moving to scsi@ list] -- Nate