Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993107AbWJURYJ (ORCPT ); Sat, 21 Oct 2006 13:24:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993108AbWJURYJ (ORCPT ); Sat, 21 Oct 2006 13:24:09 -0400 Received: from mx1.redhat.com ([66.187.233.31]:62848 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S2993107AbWJURYG (ORCPT ); Sat, 21 Oct 2006 13:24:06 -0400 Date: Sat, 21 Oct 2006 13:24:01 -0400 From: Dave Jones To: Andi Kleen Cc: patches@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [14/19] i386: Disable nmi watchdog on all ThinkPads Message-ID: <20061021172401.GD30758@redhat.com> Mail-Followup-To: Dave Jones , Andi Kleen , patches@x86-64.org, linux-kernel@vger.kernel.org References: <20061021651.356252000@suse.de> <20061021165134.7ADBB13CB4@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061021165134.7ADBB13CB4@wotan.suse.de> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1921 Lines: 46 On Sat, Oct 21, 2006 at 06:51:34PM +0200, Andi Kleen wrote: > > Even newer Thinkpads have bugs in SMM code that causes hangs with > NMI watchdog. > > Signed-off-by: Andi Kleen > > --- > arch/i386/kernel/nmi.c | 10 +++++----- > drivers/firmware/dmi_scan.c | 20 ++++++++++++++++++++ > include/linux/dmi.h | 2 ++ > 3 files changed, 27 insertions(+), 5 deletions(-) > > Index: linux/arch/i386/kernel/nmi.c > =================================================================== > --- linux.orig/arch/i386/kernel/nmi.c > +++ linux/arch/i386/kernel/nmi.c > @@ -219,11 +219,11 @@ static int __init check_nmi_watchdog(voi > int cpu; > > /* Enable NMI watchdog for newer systems. > - Actually it should be safe for most systems before 2004 too except > - for some IBM systems that corrupt registers when NMI happens > - during SMM. Unfortunately we don't have more exact information > - on these and use this coarse check. */ > - if (nmi_watchdog == NMI_DEFAULT && dmi_get_year(DMI_BIOS_DATE) >= 2004) > + Probably safe on most older systems too, but let's be careful. > + IBM ThinkPads use INT10 inside SMM and that allows early NMI inside SMM > + which hangs the system. Disable watchdog for all thinkpads */ > + if (nmi_watchdog == NMI_DEFAULT && dmi_get_year(DMI_BIOS_DATE) >= 2004 && > + !dmi_name_in_vendors("ThinkPad")) > nmi_watchdog = NMI_LOCAL_APIC; This is going to get some people scratching their heads wondering why it isn't working if they ever try nmi_watchdog on one of these. How about adding an explanitory printk ? Dave -- http://www.codemonkey.org.uk - 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/