From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: RFC: Transport identifier Date: Sat, 28 Feb 2009 08:06:34 -0700 Message-ID: <20090228150633.GQ16891@parisc-linux.org> References: <1235663301.19035.44.camel@localhost.localdomain> <49A94FEB.6050400@s5r6.in-berlin.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:50348 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790AbZB1PGw (ORCPT ); Sat, 28 Feb 2009 10:06:52 -0500 Content-Disposition: inline In-Reply-To: <49A94FEB.6050400@s5r6.in-berlin.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Stefan Richter Cc: "Martin K. Petersen" , James Bottomley , linux-scsi@vger.kernel.org On Sat, Feb 28, 2009 at 03:53:31PM +0100, Stefan Richter wrote: > Martin K. Petersen wrote: > > The thing is we need to start sending RC16 to a lot of drives very soon > > because of the 4KB thing. And as we've seen RC16 breaks a lot of junk > > devices. So we need a good indicator other than the SCSI rev. because > > that unfortunately doesn't cut it. > > /Is/ the used transport protocol a good indicator for whether a > particular target breaks by READ CAPACITY 16? I have doubts. Command > set support is independent of transport protocol support. You must admit there's a striking correlation between USB devices and completely failing to follow the SCSI spec. Our current workaround of clamping USB devices at a SCSI_2 level does avoid much of the pain. I can only hope that UAS devices actually implement SCSI instead of flicking bits at random until vista doesn't crash every time you plug it in. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."