From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756680AbZEZRex (ORCPT ); Tue, 26 May 2009 13:34:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755309AbZEZReo (ORCPT ); Tue, 26 May 2009 13:34:44 -0400 Received: from adsl-67-113-118-6.dsl.sndg02.pacbell.net ([67.113.118.6]:37697 "EHLO multivac.one-eyed-alien.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755054AbZEZReo (ORCPT ); Tue, 26 May 2009 13:34:44 -0400 Date: Tue, 26 May 2009 10:34:32 -0700 From: Matthew Dharm To: Stefan Richter Cc: =?iso-8859-1?Q?Rog=E9rio?= Brito , Alan Stern , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: Question on the removable flag of USB devices Message-ID: <20090526173432.GU28077@one-eyed-alien.net> Mail-Followup-To: Stefan Richter , =?iso-8859-1?Q?Rog=E9rio?= Brito , Alan Stern , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org References: <20090525164553.GA5572@ime.usp.br> <20090525184831.GT28077@one-eyed-alien.net> <4A1C1A79.2020500@s5r6.in-berlin.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="FWibJpkbnkY6rrXF" Content-Disposition: inline In-Reply-To: <4A1C1A79.2020500@s5r6.in-berlin.de> User-Agent: Mutt/1.4.2.3i Organization: One Eyed Alien Networks X-Copyright: (C) 2009 Matthew Dharm, all rights reserved. X-Message-Flag: Get a real e-mail client. http://www.mutt.org/ X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.12 (multivac.one-eyed-alien.net [127.0.0.1]); Tue, 26 May 2009 10:34:33 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --FWibJpkbnkY6rrXF Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 26, 2009 at 06:36:09PM +0200, Stefan Richter wrote: > Matthew Dharm wrote: > > On Mon, May 25, 2009 at 01:45:54PM -0300, Rog=E9rio Brito wrote: > >> The question is: how are devices determined to be removable or not? > >> Sorry if this question is too naive. > >=20 > > It's a bit that the device reports. The usb-storage driver passes this= bit > > to the SCSI layer. >=20 > Wasn't this bit actually about removable _media_ rather than > hotpluggable transports? (I.e. hardware where you can pull the medium > out of the drive mechanism.) So in this sense, an USB attached HDD > should actually not present itself as "removable" unless it's a SyQuest > or Zip or something like that. In fact, yes, that's the meaning of that bit. The device indicates if the storage media may be removed from the device. That said, a great many devices simply lie about this. Probably developers doing a cut-and-paste from templates which have the bit set one way or the other. The "popular" OSes don't seem to really care much about this bit... Matt --=20 Matthew Dharm Home: mdharm-usb@one-eyed-alien.= net=20 Maintainer, Linux USB Mass Storage Driver C: Like the Furby? DP: He gives me the creeps. Think the SPCA will take him? -- Cobb and Dust Puppy User Friendly, 1/2/1999 --FWibJpkbnkY6rrXF Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) iD8DBQFKHCgoHL9iwnUZqnkRAoHWAJ9RtZTPfNrJejbpxakt/T4rYt5x4wCglANz DoBtlDZK1wR/sIuS6AjnhiE= =Tzs1 -----END PGP SIGNATURE----- --FWibJpkbnkY6rrXF--