From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Dharm Subject: Re: [usb-storage] Re: [PATCH] fix Sony USB mass storage - pass larger receive buffer Date: Thu, 13 Nov 2003 11:13:44 -0800 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20031113111344.B30194@one-eyed-alien.net> References: <1068744259.13580.41.camel@patrh9> <20031113100424.A26197@beaverton.ibm.com> <1068747355.16444.22.camel@patrh9> <1068747746.16444.30.camel@patrh9> <1068747998.16444.35.camel@patrh9> <1068748629.16444.58.camel@patrh9> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="l76fUT7nc3MelDdI" Return-path: Received: from ziggy.one-eyed-alien.net ([64.169.228.100]:33807 "EHLO ziggy.one-eyed-alien.net") by vger.kernel.org with ESMTP id S264391AbTKMTOk (ORCPT ); Thu, 13 Nov 2003 14:14:40 -0500 Content-Disposition: inline In-Reply-To: <1068748629.16444.58.camel@patrh9>; from p.lavarre@ieee.org on Thu, Nov 13, 2003 at 11:37:09AM -0700 List-Id: linux-scsi@vger.kernel.org To: Pat LaVarre Cc: patmans@us.ibm.com, stern@rowland.harvard.edu, james.bottomley@steeleye.com, linux-scsi@vger.kernel.org, usb-storage@one-eyed-alien.net, ronald@kuetemeier.com, dmitrik@users.sourceforge.net, idan@idanso.dyndns.org --l76fUT7nc3MelDdI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 13, 2003 at 11:37:09AM -0700, Pat LaVarre wrote: > > > How about we blacklist all the bInterfaceSubClass that Windows does n= ot > > > regard as generic. I remember Windows does regard bInterfaceSubClass= =3D > > > x06 as generic. I think I remember there are two others. > >=20 > > grep -i generic > > in windows/inf/usbstor.inf yields, hex: > >=20 > > 08 02 50 > > 08 05 50 > > 08 06 50 > >=20 > > How about we [guess] disk writable > > [without risking mode sense] > > if we do not find bInterfaceSubClass in > > the set x 02 05 06? >=20 > In short: >=20 > Or how about we only blacklist mode sense from devices that report > bInterfaceSubClass =3D any of the x07..FF Reserved codes? Surely a device > sending us a formally Reserved code is a good first clue that it may not > behave robustly thereafter? Or maybe we just blacklist mode sense from > bInterfaceSubClass =3D xFF FormallyReservedButInformallyVendorSpecific?= =20 > Surely a device sending us that code is an even better first clue that > it may not behave robustly thereafter? Our experience tells us that xFF is often used because designers are one of the following: (a) lazy (b) incompetient (c) driven by marketing, which wants to load an .inf so their device seems 'special' (custom icons, etc.) So xFF doesn't really tell us, deterministically, anything at all. Knowing that the device is direct-access, however, implies very strongly that MODE_SENSE[_10] is a bad idea. Matt --=20 Matthew Dharm Home: mdharm-usb@one-eyed-alien.= net=20 Maintainer, Linux USB Mass Storage Driver Okay, this isn't funny anymore! Let me down! I'll tell Bill on you!! -- Microsoft Salesman User Friendly, 4/1/1998 --l76fUT7nc3MelDdI Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE/s9foIjReC7bSPZARAuixAJ9P5Y+aw0AB1RYqOJK+jcLVhLF1UACgjsDt u2fYwN/al3L7dkNYC9DUu5Y= =LS8h -----END PGP SIGNATURE----- --l76fUT7nc3MelDdI--