Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 25 Sep 2002 23:43:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 25 Sep 2002 23:43:21 -0400 Received: from ausadmmsps306.aus.amer.dell.com ([143.166.224.101]:18182 "HELO AUSADMMSPS306.aus.amer.dell.com") by vger.kernel.org with SMTP id ; Wed, 25 Sep 2002 23:43:20 -0400 X-Server-Uuid: c21c953d-96eb-4242-880f-19bdb46bc876 Message-ID: <20BF5713E14D5B48AA289F72BD372D68C1E8C2@AUSXMPC122.aus.amer.dell.com> From: Matt_Domsch@Dell.com To: greg@kroah.com cc: mochel@osdl.org, linux-kernel@vger.kernel.org Subject: RE: devicefs requests Date: Wed, 25 Sep 2002 22:48:31 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) X-WSS-ID: 118C5C1A890286-01-01 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1621 Lines: 37 > Um, what 64-bit unique id? USB devices do not have such a thing. The EDD spec (http://www.t13.org/docs2002/d1572r0.pdf - T13 committee project 1572D BIOS Enhanced Disk Drive Services - 3) says: USB identifier: 64-bit Serial Number as defined in the USB Mass Storage specifications I assume that they mean the USB Mass Storage spec v1.0 (http://www.usb.org/developers/data/devclass/usbmassbulk_10.pdf) section 4.1.1 - Serial Number, which is 12-16 bytes long. drivers/usb/storage/usb.c turns that into a 16-byte GUID in storage_probe(). I hadn't gotten so far as to see that these two specs don't agree for USB - I'd been looking at the IDE and SCSI descriptions so far. It wouldn't be the first time the EDD spec needed editing, and given that few (if any) BIOSs yet implement it apart from SCSI, is reason for the confusion. I don't think Dell has a T13 committee representative right now, but I'll see if we have a process for getting this cleared up through official channels. As I'm not a USB expert, would you care to comment on the right way to handle this (i.e. instead of a 64-bit serial number, use the 16-byte GUID)? Thanks, Matt -- Matt Domsch Sr. Software Engineer, Lead Engineer, Architect Dell Linux Solutions www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com #1 US Linux Server provider for 2001 and Q1/2002! (IDC May 2002) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/