From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267378AbTGVIUv (ORCPT ); Tue, 22 Jul 2003 04:20:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268013AbTGVIUv (ORCPT ); Tue, 22 Jul 2003 04:20:51 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:9179 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S267378AbTGVIUu (ORCPT ); Tue, 22 Jul 2003 04:20:50 -0400 Date: Tue, 22 Jul 2003 10:35:36 +0200 (MEST) Message-Id: <200307220835.h6M8Zaqd024427@harpo.it.uu.se> From: Mikael Pettersson To: rl@hellgate.ch Subject: Re: APIC support prevents power off Cc: linux-kernel@vger.kernel.org, mingo@redhat.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Jul 2003 11:54:14 +0200, Roger Luethi wrote: >On Mon, 21 Jul 2003 03:13:52 +0200, Mikael Pettersson wrote: >> On Sun, 20 Jul 2003 16:36:13 +0200, Roger Luethi wrote: >> >On some UP boards (e.g. ASUS A7A266) enabling support for local APICs keeps >> >the machine from powering off on shutdown. It will just hang instead. >> > >> >This has been observed by others before [1]. A warning in the respective >> >configuration note seems in order (or a proper fix if anybody has one). >> >> Insufficient data to draw anti-local-APIC conclusions. >> - ensure you have the latest BIOS > >I tend not to touch the BIOS unless I have reason to believe an update will >fix an actual problem. Powering off invokes the BIOS. BIOSen are known to have bugs. You really should check if a BIOS update is available. >> - if you're using APM, ensure that CPU_IDLE and DISPLAY_BLANK are >> disabled, and that APM isn't built as a module >> (these things are known to cause APM hangs in UP APIC systems) >> - if you're using ACPI, try without ACPI, or at least with ACPI not >> doing any power management > >Your suggestions match my current configuration: Your APM/ACPI config seems Ok, but what does CONFIG_SMP look like? Enabling SMP disables APM's power off code, unless one boots with apm=power-off. Did your kernel have to actually enable the local APIC, or did the BIOS boot us with it already enabled? Please send me a dmesg from a boot with local APIC support enabled. I can't seem to find any place where we disable the local APIC on shutdown; reboot seems Ok but not poweroff (as far as I can see). I think this might explain why some BIOSen hang at poweroff. /Mikael