Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S275092AbTHMOYp (ORCPT ); Wed, 13 Aug 2003 10:24:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S275201AbTHMOYp (ORCPT ); Wed, 13 Aug 2003 10:24:45 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:40622 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S275092AbTHMOYm (ORCPT ); Wed, 13 Aug 2003 10:24:42 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16186.18984.335521.224346@gargle.gargle.HOWL> Date: Wed, 13 Aug 2003 16:24:40 +0200 From: Mikael Pettersson To: Ruben Puettmann Cc: linux-kernel@vger.kernel.org Subject: Re: 2.4.22 APM problems with IBM Thinkpad's In-Reply-To: <20030813133126.GA26337@puettmann.net> References: <20030813123119.GA25111@puettmann.net> <16186.14686.455795.927909@gargle.gargle.HOWL> <20030813133126.GA26337@puettmann.net> X-Mailer: VM 6.90 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1916 Lines: 44 Ruben Puettmann writes: > On Wed, Aug 13, 2003 at 03:13:02PM +0200, Mikael Pettersson wrote: > > > > This sounds like a well-known APM/local-APIC clash. > > nice to know ... > > > > Never ever use DISPLAY_BLANK if you also have SMP or UP_APIC. > > not nice so ;-( how is it with acpi? Same problem? > > > With APIC support enabled (SMP or UP_APIC), APM must be constrained: > > DISPLAY_BLANK off > > CPU_IDLE off > > built-in driver, not module > > Why will this not be disabled in make *config so that nobody will run in > this problem? > > > This is because the apm driver does BIOS calls, and many BIOSen > > (including the code in graphics cards, e.g. all Radeons it seems) > > like to hang if a local APIC timer interrupt arrives. Several reasons: - The interaction wasn't understood initially, and some problems didn't start appearing until late last year. The problems are also system & configuration dependent. Case in point #1: my P3B-F and P4T-E ASUS mainboards never had problems until they started running 2.5 kernels, where HZ==1000 greatly increased the likelihood of a local APIC timer interrupt while in BIOS screen blanking code. Case in point #2: my TUSL2-C ASUS mobo (RIP) worked great until I switched from a Millenium to a Radeon 8500, and found that it hung because of local APIC timer interrupts while in BIOS screen blanking code, even in 2.4 kernels. - Fixing the APM driver would require that someone who understands it modifies it to avoid BIOS calls (other than suspend/resume) when UP_APIC is active. I'm not that person. - The problems can be worked around by avoiding misconfigurations. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/