From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752033AbXDDRi7 (ORCPT ); Wed, 4 Apr 2007 13:38:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752044AbXDDRi7 (ORCPT ); Wed, 4 Apr 2007 13:38:59 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:55752 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752033AbXDDRi6 (ORCPT ); Wed, 4 Apr 2007 13:38:58 -0400 Date: Wed, 4 Apr 2007 12:38:56 -0500 To: David Woodhouse Cc: Brad Boyer , linuxppc-dev@ozlabs.org, Paul Mackerras , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Stop pmac_zilog from abusing 8250's device numbers. Message-ID: <20070404173856.GU4922@austin.ibm.com> References: <1175610345.2665.15.camel@shinybook.infradead.org> <17938.57292.870224.132415@cargo.ozlabs.ibm.com> <1175642916.10567.24.camel@shinybook.infradead.org> <20070403212928.GA12951@cynthia.pants.nu> <1175644642.10567.31.camel@shinybook.infradead.org> <20070403221002.GA13210@cynthia.pants.nu> <1175648051.10567.61.camel@shinybook.infradead.org> <20070403230908.GA13471@cynthia.pants.nu> <20070404162234.GS4922@austin.ibm.com> <1175704494.2774.33.camel@shinybook.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1175704494.2774.33.camel@shinybook.infradead.org> User-Agent: Mutt/1.5.11 From: linas@austin.ibm.com (Linas Vepstas) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 04, 2007 at 12:34:53PM -0400, David Woodhouse wrote: > On Wed, 2007-04-04 at 11:22 -0500, Linas Vepstas wrote: > > The biggest problem would seem to be that the assignment would > > depend on the detection order; there don't seem to be unique > > id's that would help udev consistently assign device names in > > consistent order. > > Of course there are. The different types of ports have different device > numbers. As long as we don't do anything silly like putting all the > serial drivers on the same major number, we can tell them apart > relatively well. Sure, but if two different pci serial cards are moved around to different pci slots, they'll be detected in a different order. Similarly if one has some usb-to-serial converter that might get plugged in after boot, or maybe some serial port that shows up only when a laptop is docked into a docking station. --linas