Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262425AbUCWKma (ORCPT ); Tue, 23 Mar 2004 05:42:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262450AbUCWKm3 (ORCPT ); Tue, 23 Mar 2004 05:42:29 -0500 Received: from jurand.ds.pg.gda.pl ([153.19.208.2]:21143 "EHLO jurand.ds.pg.gda.pl") by vger.kernel.org with ESMTP id S262425AbUCWKmY (ORCPT ); Tue, 23 Mar 2004 05:42:24 -0500 Date: Tue, 23 Mar 2004 11:42:23 +0100 (CET) From: "Maciej W. Rozycki" To: Guennadi Liakhovetski Cc: "Richard B. Johnson" , Robert_Hentosh@Dell.com, fleury@cs.auc.dk, linux-kernel@vger.kernel.org Subject: RE: spurious 8259A interrupt In-Reply-To: Message-ID: References: Organization: Technical University of Gdansk MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1558 Lines: 31 On Tue, 23 Mar 2004, Guennadi Liakhovetski wrote: > Yes, I saw this your explanation. Thanks again. But, I am not getting > those errors with local APIC disabled. That's why I thought "local APIC -> Is the local APIC normally disabled, i.e. do you see a message like: "Local APIC disabled by BIOS -- reenabling." when you boot with your local APIC enabled? That might explain the difference. > timer -> spurious interrupts." Maybe I am wrong. But I also can't see how > enabling the lapic can cause, e.g., power supply glitches to become > visible. I would be happy and grateful to hear an explanation. I don't know what setup you are useing, but depending on the implementation, the local APIC may treat ExtINTA interrupts as level-triggered or as edge-triggered. The latter setup is a design error in my opinion (the 8259A has a level-triggered output) and may lead to what you observe. As the local APIC latches edge-triggered interrupts it receives (unlike the 8259A) a glitch on an interrupt line does not have to last long enough for a CPU to accept it for a spurious interrupt to be recorded. -- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available + - 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/