Return-path: Received: from netrider.rowland.org ([192.131.102.5]:47160 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752937AbZKDD5z (ORCPT ); Tue, 3 Nov 2009 22:57:55 -0500 Date: Tue, 3 Nov 2009 22:57:59 -0500 (EST) From: Alan Stern To: Oliver Neukum cc: Dan Williams , Matthew Dharm , Frank Schaefer , , Subject: Re: [PATCH] ar9170usb: add mode-switching for AVM Fritz!WLAN USB N devices in cdrom mode In-Reply-To: <200911040055.01441.oliver@neukum.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 4 Nov 2009, Oliver Neukum wrote: > > If power is turned off, there's nothing we can do about it. Once that > > happens, it doesn't make much difference whether the mode switch occurs > > in usb-storage or from a userspace program. The old device instance > > will go away and a new one will appear. > > That is what happens and what must happen if we switch mode in user space. > In kernel space, the kernel could repeat the mode switch. How? Doesn't the mode switch cause a change in the configuration, interface, or endpoint descriptors? The end result would be the same -- the old device instance would go away and a new one would appear. Alan Stern