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Date: Mon, 16 Jun 2008 13:36:23 +0100
From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Martin Michlmayr <tbm@cyrius.com>
Cc: linux-kernel@vger.kernel.org, keithp@keithp.com,
       linux-acpi@vger.kernel.org
Subject: Re: kernel panic when plugging in USB device and closing lid
Message-ID: <20080616123623.GA21609@srcf.ucam.org>
References: <20080616123238.GA2852@deprecation.cyrius.com>
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On Mon, Jun 16, 2008 at 02:32:38PM +0200, Martin Michlmayr wrote:

> I briefly talked to Matthew Garrett on IRC who said this "looks like
> state corruption".  He asked me to set /proc/acpi/video/blah/DOS to 7
> and see whether I could still reproduce the problem.  After setting
> this value, I no longer see the kernel panic.  Matthew: "Right.  The
> lid-close SMM seems to blow things up some of the time."

If DOS is set to 1, the BIOS seems to do something that makes the kernel 
massively unhappy. Disabling the automatic display switch control avoids 
this, which makes me think it's a BIOS bug of some description.

-- 
Matthew Garrett | mjg59@srcf.ucam.org
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