From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: use_10_for_ms revisited? Date: Sun, 29 Jun 2003 03:27:38 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3EFE94EA.7030909@pobox.com> References: <3EFE8784.4000101@pobox.com> <20030628233824.H26995@one-eyed-alien.net> <3EFE8B7B.2000109@pobox.com> <20030628235413.I26995@one-eyed-alien.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:32647 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S265591AbTF2HNb (ORCPT ); Sun, 29 Jun 2003 03:13:31 -0400 In-Reply-To: <20030628235413.I26995@one-eyed-alien.net> List-Id: linux-scsi@vger.kernel.org To: Matthew Dharm Cc: linux-scsi@vger.kernel.org Matthew Dharm wrote: > I'm somewhat concerned that, just as we're finding something that works, > we're going to go off in another direction. > > I certainly wouldn't mind removing the code that manipulates the SCSI > revision number. I'm talking about code in the scsi core that does stuff like ("if scsi_level <= 2" ...), which is wrong for MMC, where version==0 is a valid value on modern atapi and usb devices. > But, the 6-to-10 conversion code (at least for USB) is all about to go > away, once we settle on how sr.c (and friends) should handle use_10_for_ms > -- so one of your reasons to change all this is already moot. Not really, see below. > I guess, in part, I'm hesitant to rely on fields in the INQUIRY data that > nobody has checked to verify that they are actually useful. Most USB > devices are made on ultra-low testing, and commonly have bad bits in any > field that isn't used by Windows or MacOS. MMC-4 is the culmination of the stuff that's in the field now. Really, sr wants to know "are you mmc-compliant?" If the answer is yes, it should only use MMC-defined commands (mode sense 10, etc.). use_10_for_ms is a subset of that. Jeff