From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753963AbYIRNKY (ORCPT ); Thu, 18 Sep 2008 09:10:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753840AbYIRNKH (ORCPT ); Thu, 18 Sep 2008 09:10:07 -0400 Received: from main.gmane.org ([80.91.229.2]:60365 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753265AbYIRNKG (ORCPT ); Thu, 18 Sep 2008 09:10:06 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Simon Farnsworth Subject: Re: ACPI "Soft-off" power button only rebooting system, not powering off Date: Thu, 18 Sep 2008 13:25:56 +0100 Message-ID: <48D248D4.40103@farnz.org.uk> References: <76366b180809162150o51701a1fk209af4e84ffc5674@mail.gmail.com> <20080917101809.GA4771@elf.ucw.cz> <76366b180809170533t6962f3d0qf67278b2e9ff6bd0@mail.gmail.com> <20080918110635.GF27832@elf.ucw.cz> <48D245BF.7060902@earthlink.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org Cc: Pavel Machek , Andrew Paprocki , LKML X-Gmane-NNTP-Posting-Host: host217-35-101-6.in-addr.btopenworld.com User-Agent: Thunderbird 2.0.0.9 (X11/20071115) In-Reply-To: <48D245BF.7060902@earthlink.net> X-Enigmail-Version: 0.95.7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Stephen Clark wrote: > Pavel Machek wrote: >> On Wed 2008-09-17 08:33:50, Andrew Paprocki wrote: >>> On Wed, Sep 17, 2008 at 6:18 AM, Pavel Machek wrote: >>>> On Wed 2008-09-17 00:50:03, Andrew Paprocki wrote: >>>>> I have an AMD / Award BIOS based system which does not properly shut >>>>> off when I hold down the power button for 4 seconds. The BIOS is >>>>> configured to have "Soft-off" set to "Delay for 4 seconds" which is >>>>> supposed to power the machine off if the button is held that long. >>>>> >>>>> I first thought this could be a BIOS bug, but this *only* appears to >>>>> happen while Linux is running. If the computer is running WinXP, it >>>> Well, so the BIOS is broken. 4second hold should power down the >>>> machine regardless of the operating system. >>> Yes, I agree.. I just find it strange that it works on the BIOS screen >>> as well as in GRUB, but as soon as Linux boots, it no longer works. >>> Since it works under WinXP, there must be some way to get it to work >>> properly from the OS side even it if means working around the bug >>> somehow. >> >> Try noapic/nolapic/nosmp etc... and ask your vendor to fix the bios ;-). >> > Why do you say it is the BIOS when it shuts down properly from the GRUB > prompt or from in WINXP? > Because it's only the BIOS that can cause this behaviour. When you push the power button, the BIOS is invoked. If you release within 4 seconds, the BIOS sends an ACPI event to the running OS, telling it that the power button has been pushed. If you hold it down for 4 or more seconds, the BIOS is supposed to shut the machine down without the OS knowing what's happening (no ACPI events, just a loss of power). From your problem description, the BIOS is noticing *something* about the way Linux sets things up, and *choosing* to reboot instead of cutting the power. GRUB doesn't touch hardware without BIOS help, so is unlikely to change the system state in a way that tickles this BIOS bug; similarly, BIOSes are tested against current Windows versions by vendors, so they'll have hacked it around until it worked there. -- Hope this helps, Simon Farnsworth