Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266304AbUAVRtz (ORCPT ); Thu, 22 Jan 2004 12:49:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266310AbUAVRty (ORCPT ); Thu, 22 Jan 2004 12:49:54 -0500 Received: from aun.it.uu.se ([130.238.12.36]:38123 "EHLO aun.it.uu.se") by vger.kernel.org with ESMTP id S266304AbUAVRtt (ORCPT ); Thu, 22 Jan 2004 12:49:49 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16400.3366.286902.721704@alkaid.it.uu.se> Date: Thu, 22 Jan 2004 18:49:26 +0100 From: Mikael Pettersson To: Linus Torvalds Cc: Karol Kozimor , "Georg C. F. Greve" , "Nakajima, Jun" , Martin Loschwitz , linux-kernel@vger.kernel.org, "Brown, Len" , acpi-devel@lists.sourceforge.net Subject: Re: [ACPI] Re: PROBLEM: ACPI freezes 2.6.1 on boot In-Reply-To: References: <7F740D512C7C1046AB53446D3720017361885C@scsmsx402.sc.intel.com> <20040122120854.GB3534@hell.org.pl> <16399.55109.244040.516731@alkaid.it.uu.se> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1976 Lines: 48 Linus Torvalds writes: > > > On Thu, 22 Jan 2004, Mikael Pettersson wrote: > > > Karol Kozimor writes: > > > > > > diff -Bru linux-2.6.0-test8/arch/i386/kernel/apic.c patched/arch/i386/kernel/apic.c > > > --- linux-2.6.0-test8/arch/i386/kernel/apic.c 2003-10-18 05:43:36.000000000 +0800 > > > +++ patched/arch/i386/kernel/apic.c 2003-10-30 23:17:50.000000000 +0800 > > > @@ -836,8 +836,8 @@ > > > { > > > unsigned int lvtt1_value, tmp_value; > > > > > > - lvtt1_value = SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV) | > > > - APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR; > > > + lvtt1_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR; > > > + > > > apic_write_around(APIC_LVTT, lvtt1_value); > > > > What is the purpose of this change? > > I don't remember seeing this before on LKML. (I don't have time to read bugzilla.) > > Hmm.. It does seem to fix things for a couple of people, so it looks > interesting. > > As far as I can tell, the _only_ thing it does is to change the timer base > from "DIV" to "CLKIN". I seem to have misplaced my ia-32 "volume 3" thing, > but I have an old one for a pentium, and that one doesn't actually > haev the timer-base thing at all - and marks those bits as "reserved". > > So it is entirely possible that the only safe value to write there is 0. Confirmed. Those bits (18 and 19 in LVTT) are marked reserved in the latest IA32 Volume 3. I have no idea where this APIC_TIMER_BASE came from (maybe some ancient discrete LAPIC thing?), but we almost certainly shouldn't write anything but zero to them. > So I'm inclined to apply the patch, but it would be better if somebody who I agree. The patch should be applied. /Mikael - 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/