linux-kernel - Re: [patches] Re: [PATCH] [14/19] i386: Disable nmi watchdog on all ThinkPads

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Date:	Sat, 21 Oct 2006 20:11:56 +0200
From:	Andi Kleen <ak@...e.de>
To:	patches@...-64.org
Cc:	Dave Jones <davej@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [patches] Re: [PATCH] [14/19] i386: Disable nmi watchdog on all ThinkPads


>  > -	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 ?

When you enable it manually then NMI_DEFAULT won't be set and this code
is never executed.

BTW their machines will likely not stay up long enough that they can
see the printk (unless Lenovo fixes that particular bug in the future,
they are aware of it)

-Andi
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