From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965671AbXCVEXy (ORCPT ); Thu, 22 Mar 2007 00:23:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965681AbXCVEXy (ORCPT ); Thu, 22 Mar 2007 00:23:54 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:52076 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965671AbXCVEXy (ORCPT ); Thu, 22 Mar 2007 00:23:54 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.1 From: Keith Owens To: Bjorn Helgaas cc: linux-kernel@vger.kernel.org, len.brown@intel.com, Andrew Morton , Russell King Subject: Re: PNPACPI probes serial twice, messes up serial console In-reply-to: Your message of "Wed, 21 Mar 2007 10:35:38 MDT." <200703211035.39340.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 22 Mar 2007 15:23:51 +1100 Message-ID: <11466.1174537431@kao2.melbourne.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bjorn Helgaas (on Wed, 21 Mar 2007 10:35:38 -0600) wrote: >On Tuesday 20 March 2007 08:32, Bjorn Helgaas wrote: >> On Tuesday 20 March 2007 00:46, Keith Owens wrote: >> > Booting with 'console=tty console=ttyS0,9600'. The serial console on >> > ttyS0 (0x3f8, irq 4) is probed twice, once from serial8250_init() and >> > again from serial_pnp_probe(). >> >> I played with this last summer, but was too timid to finish it >> and post it. My plan was to remove the legacy SERIAL_PORT_DFNS, >> make platform devices for them, and only register the platform >> devices in the absence of PNP. >> >> My motivation at the time was to prevent 8250 from claiming IRDA >> devices that happened to live at legacy UART addresses. I also >> wanted to make IRDA (smsc-ircc2 in my case) smart enough to use >> PNP to locate its devices, since 8250 would no longer claim them. >> >> Here's the dusty patch (against 2.6.18-rc1-mm2). If it seems >> like a reasonable thing to do, I can update it, polish it up, >> add a changelog, and post it. > >Keith, does this patch help? Russell didn't complain about it, so >if it fixes your problem, maybe we could put it in -mm and see if >it breaks anything else. The aim of the patch looks sensible, but it will not compile for 2.6.21-rc4. 8250_x86.c tests pnp_platform_devices, which does not exist. Also the combination of CONFIG_SERIAL_8250_X86=y and CONFIG_SERIAL_8250_PNP=m would result in 8250_x86.o being built into vmlinux but referring to serial8250_nopnp in module 8250_pnp.o, kernel to module references are tricky.