From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762821AbYDURnq (ORCPT ); Mon, 21 Apr 2008 13:43:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754256AbYDURng (ORCPT ); Mon, 21 Apr 2008 13:43:36 -0400 Received: from terminus.zytor.com ([198.137.202.10]:37514 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961AbYDURnf (ORCPT ); Mon, 21 Apr 2008 13:43:35 -0400 Message-ID: <480CD178.2070806@zytor.com> Date: Mon, 21 Apr 2008 13:40:08 -0400 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Bart Van Assche CC: Frantisek Rysanek , linux-kernel@vger.kernel.org Subject: Re: What pokes the ISA IO port of 0x211 ? References: <480C92C9.18283.A24BB91B@localhost> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bart Van Assche wrote: > On Mon, Apr 21, 2008 at 1:12 PM, Frantisek Rysanek > wrote: >> I'm dealing with an embedded PC motherboard that contains some custom >> circuitry (GPIO), accessible via an ISA IO range between 0x200 and >> 0x218. >> >> There's an interesting issue with this in recent Linux (tried >> 2.6.22.6 and 2.6.24.2): something probes IO port 0x211 on boot, which >> happens to be an add-on buzzer control port - effectively the kernel >> boot launches an accoustic alarm :-) >> >> Any ideas what this could be? > > Did you already have a look at /proc/ioports ? This file should > contain every range of ISA bus address in use by any kernel component. > This might not be the case if a probe fails and the driver unload itself. It might be easiest to put in a hack in the kernel by hacking outb/outw/outl and print stack trace when called when trying to poke this port. For what it's worth, this port is specified as "Game Blaster" in the Interrupt List. -hpa