From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: PATCH: usb-storage-set-last-sector-bug-flag.patch Date: Fri, 25 Jan 2008 11:12:21 -0600 Message-ID: <1201281141.3119.41.camel@localhost.localdomain> References: <20080120205625.GB28842@kroah.com> <20080123181239.GA21836@kroah.com> <4798C5B4.1000208@s5r6.in-berlin.de> <20080124172158.GC9665@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080124172158.GC9665@kroah.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-usb-devel-bounces@lists.sourceforge.net Errors-To: linux-usb-devel-bounces@lists.sourceforge.net To: Greg KH Cc: USB development list , linux-scsi@vger.kernel.org, USB Storage list , linux-usb@vger.kernel.org, David Brown , Stefan Richter , Alan Stern , Hans de Goede , Boaz Harrosh , Matthew Dharm List-Id: linux-scsi@vger.kernel.org On Thu, 2008-01-24 at 09:21 -0800, Greg KH wrote: > On Thu, Jan 24, 2008 at 06:07:00PM +0100, Stefan Richter wrote: > > Greg KH wrote: > > > I just am worried that we are > > > now suddenly keeping access from the last sector for devices that > > > currently did work just fine. > > > > This new workaround doesn't prevent access to the last sector. It only > > breaks up a multi-sector access which would also reach the last sector > > into several (two? I'm too lazy to look back in the mail thread) > > accesses, in order to access the last sector in a dedicated > > single-sector access. > > > > So that's very differently to the fix-capacity workaround. The > > fix-capacity workaround manipulates the READ CAPACITY parameter data. > > Therefore the fix-capacity workaround is unsafe for non-buggy devices. > > > > The last-sector-(access-)bug workaround _only_ modifies the command > > stream which is sent to the device. A dangerous command is replaced by > > equivalent safe commands. These commands are luckily safe for _all_ > > devices, buggy and non-buggy ones. The only cost of this workaround is > > (1.) the code, (2.) the runtime/ bandwidth/ latency overhead for > > accesses which reach the last sector. > > Ok, thanks for explaining it better. I have no objection to this change > anymore. So, for forms sake to take this through the SCSI tree I need at least one USB person to ack it ... James ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel