From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992527AbXDDAZo (ORCPT ); Tue, 3 Apr 2007 20:25:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992524AbXDDAZn (ORCPT ); Tue, 3 Apr 2007 20:25:43 -0400 Received: from adsl-216-102-214-42.dsl.snfc21.pacbell.net ([216.102.214.42]:51319 "EHLO cynthia.pants.nu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992519AbXDDAZm (ORCPT ); Tue, 3 Apr 2007 20:25:42 -0400 X-Greylist: delayed 2450 seconds by postgrey-1.27 at vger.kernel.org; Tue, 03 Apr 2007 20:25:42 EDT Date: Tue, 3 Apr 2007 15:10:02 -0700 From: Brad Boyer To: David Woodhouse Cc: Paul Mackerras , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Stop pmac_zilog from abusing 8250's device numbers. Message-ID: <20070403221002.GA13210@cynthia.pants.nu> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1175644642.10567.31.camel@shinybook.infradead.org> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 03, 2007 at 07:57:22PM -0400, David Woodhouse wrote: > > The TTY_MAJOR should have never belonged to 8250.c in the first place. > > I know it's just my opinion, but I think this major device should be > > owned by the serial core, and it shouldn't matter what chip drives each > > individual port. Each hardware driver should just register with the > > core how many ports it has and should be allocated from the same range. > > Yeah, because that works out really well for Ethernet devices and SCSI > disks, with different numbers every day of the week according to what > order we happen to load drivers in. :) It just leads to the problem ethernet has on BSD/Solaris/etc. You have to ask yourself "is the ethernet on this system le0 or hme0 or maybe something else entirely?" in this case. I agree it does solve the issue of detection order breaking the configuration, but it is less than ideal. I think the issue of the devices shuffling around is less likely to be a problem on serial, although we don't have the nice uniqueness of hardware identifiers that was used to do device renaming in ethernet. I suppose my opinion on this shows that I didn't come from the x86 side of Linux. The breakdown on this argument seems to have always been that the x86 people wanted 8250 to own ttyS* and most others wanted it shared. I know it was that way when m68k tried to merge in their serial framework that did allow such sharing across any number of hardware drivers. Brad Boyer flar@allandria.com