Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754796Ab0DZTeY (ORCPT ); Mon, 26 Apr 2010 15:34:24 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:38265 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751306Ab0DZTeX (ORCPT ); Mon, 26 Apr 2010 15:34:23 -0400 Date: Mon, 26 Apr 2010 15:34:22 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: =?ISO-8859-1?Q?Micha=C5=82_Nazarewicz?= cc: Josua Dietze , Daniel Mack , Marek Szyprowski , Kernel development list , USB list , Kyungmin Park Subject: Re: USB gadget with drivers "on board" In-Reply-To: <4BD5CF3C.9020406@draisberghof.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1514 Lines: 36 On Mon, 26 Apr 2010, Josua Dietze wrote: > Michał Nazarewicz schrieb: > > > On Mon, 26 Apr 2010 16:16:05 +0200, Daniel Mack wrote: > >> Are you sure they don't do exactly that by running two interfaces in > >> the same configuration? > > > > Yes, I'm sure. I've investigated an USB GSM modem which, when plugged > > for the first time reports as mass storage (single configuration, single > > interface) and when drivers are installed as a full blown composite > > gadget. I still haven't figured out how it does that. > > > These are the notorious mode switching devices. In Windows, they > obviously install a special storage driver doing one specific action > on each following plugging. > This action - some storage or control command - will "flip" the > device, making it "disconnect" and returning as a completely different > composite device. > > Storage commands used for this procedure range from "SCSI rezero" over > "passthrough" to "SCSI eject", or involve vendor specific stuff. I was going to say the same thing. For ease of use, I recommend using a "SCSI eject" to trigger the mode change. That way, Linux users who don't have the usb-modeswitch program installed can get the same effect by running eject. Alan Stern -- 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/