Return-path: Received: from smtp-out003.kontent.com ([81.88.40.217]:56401 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbZKDJbj (ORCPT ); Wed, 4 Nov 2009 04:31:39 -0500 From: Oliver Neukum To: Alan Stern Subject: Re: [PATCH] ar9170usb: add mode-switching for AVM Fritz!WLAN USB N devices in cdrom mode Date: Wed, 4 Nov 2009 10:11:38 +0100 Cc: Dan Williams , Matthew Dharm , Frank Schaefer , linux-wireless@vger.kernel.org, linux-usb@vger.kernel.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200911041011.38367.oliver@neukum.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: Am Mittwoch, 4. November 2009 04:57:59 schrieb Alan Stern: > 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. But it switches to a known state which we could use to trigger a switch and recompare after the switch. Regards Oliver