From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758481AbXELRe5 (ORCPT ); Sat, 12 May 2007 13:34:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754848AbXELRet (ORCPT ); Sat, 12 May 2007 13:34:49 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:50363 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754670AbXELRes (ORCPT ); Sat, 12 May 2007 13:34:48 -0400 Date: Sat, 12 May 2007 10:34:41 -0700 From: Andrew Morton To: Tear Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: Dell Optiplex GX240, ACPI and APIC Message-Id: <20070512103441.a21194fc.akpm@linux-foundation.org> In-Reply-To: <229533.82694.qm@web63609.mail.re1.yahoo.com> References: <229533.82694.qm@web63609.mail.re1.yahoo.com> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 12 May 2007 07:04:25 -0700 (PDT) Tear wrote: > Summary: If ACPI is not enabled but APIC is, > then there is trouble on Dell Optiplex GX240. > If both are enabled or if both are disabled, then > everything is fine. The attached patch removes > Dell Optiplex GX240 from the ACPI blacklist. > > --- > > Hello, > > I have a Dell Optiplex GX240 and when I boot Linux, ACPI > gets set up by only acpi=ht. dmesg shows the following line: > > DELL GX240 detected: force use of acpi=ht > > Everything seemed to be fine. However, I discovered that > everything is not fine. The USB controller works so slowly > that copying a few (uncached) 1 megabyte large photos from > a USB-enabled digital camera takes many minutes instead of > a couple of seconds. > > I am using Linux 2.6.21.1 on a Debian 4.0 ("Etch") system. > > I thought that this might be related to ACPI. So I tried > to boot with _only_ "acpi=force" appended to the kernel > command line. Voila, the USB controller started to work > at full speed and copying photos from my digital camera > took only seconds. > > I tested the system with "acpi=force" and could not find > anything which did not work. So, can we please remove > Dell Optiplex GX240 from the blacklist in > > ..../arch/i386/kernel/acpi/boot.c > > ? The attached patch does just that: It removes Dell > Optiplex GX240 from the ACPI blacklist. > > I thought that this might be related to interrupts and > APIC as well. (Note that this is APIC, not ACPI.) I tried > booting with _only_ "noapic" and "nolapic" appended to the > command line. Again, the USB controller started to work > at full speed. > > If removing Dell Optiplex GX240 from the ACPI blacklist > is not wanted/possible, then is there a way to disable > APIC and LAPIC (note that this is APIC not ACPI) by > default on Dell GX240 machines? (I.e. Can one patch > the kernel so that APIC and LAPIC isn't used on > these machines? - I know that I can use the noapic > and nolapic options on the kernel command line.) > > Thank you for your attention. > > - Tear > > Note: Please include me in CC of your replies. > > > --- linux-2.6.21.1.orig/arch/i386/kernel/acpi/boot.c 2007-05-01 17:10:30.000000000 +0300 > +++ linux-2.6.21.1/arch/i386/kernel/acpi/boot.c 2007-05-01 20:31:53.000000000 +0300 > @@ -971,14 +971,6 @@ > }, > { > .callback = force_acpi_ht, > - .ident = "DELL GX240", > - .matches = { > - DMI_MATCH(DMI_BOARD_VENDOR, "Dell Computer Corporation"), > - DMI_MATCH(DMI_BOARD_NAME, "OptiPlex GX240"), > - }, > - }, > - { > - .callback = force_acpi_ht, > .ident = "HP VISUALIZE NT Workstation", > .matches = { > DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"), > Thanks. Let's cc the acpi list. The origin of that blacklist entry appears to be lost in the mists of time. git-blame got tripped up by an intervening Lindent run and my gittiness is insufficient for tracking changes before that.