Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759981Ab3HNO13 (ORCPT ); Wed, 14 Aug 2013 10:27:29 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:45468 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1759901Ab3HNO11 (ORCPT ); Wed, 14 Aug 2013 10:27:27 -0400 Date: Wed, 14 Aug 2013 10:27:26 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Mark Brown cc: Greg Kroah-Hartman , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Felipe Balbi , Grant Likely , , , Subject: Re: Non-enumerable devices on USB and other enumerable buses In-Reply-To: <20130814113848.GP6427@sirena.org.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1218 Lines: 30 On Wed, 14 Aug 2013, Mark Brown wrote: > On Mon, Aug 12, 2013 at 09:04:00PM -0400, Alan Stern wrote: > > > The bus code would need hooks installed wherever the platform wants to > > do something extra. This could end up growing to a lot of hooks. How > > can the whole thing be done in a reasonable fashion? > > I'd expect that we're just looking at hooks around connection and > disconnection here here - if we're looking at much more it seems like we > must be doing something wrong. Connection and disconnection of what? In the example mentioned earlier, the GPIOs to power an on-board USB hub would have to be initialized when the host controller was started. You wouldn't want to wait for the on-board hub to be detected, because without those GPIOs set properly, it never would be discovered on the USB bus. Right? Perhaps the platform-level code would need to hook into the places where the discoverable bus is registered and unregistered. 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/