From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764276AbXKOSFW (ORCPT ); Thu, 15 Nov 2007 13:05:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756889AbXKOSFK (ORCPT ); Thu, 15 Nov 2007 13:05:10 -0500 Received: from smtp-out002.kontent.com ([81.88.40.216]:52410 "EHLO smtp-out002.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753077AbXKOSFJ (ORCPT ); Thu, 15 Nov 2007 13:05:09 -0500 From: Oliver Neukum To: "Maciej W. Rozycki" Subject: Re: question on odd APIC behavior Date: Thu, 15 Nov 2007 19:05:02 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: linux-kernel@vger.kernel.org References: <200711150054.34312.oliver@neukum.org> <200711151627.25622.oliver@neukum.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200711151905.03005.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Am Donnerstag 15 November 2007 schrieb Maciej W. Rozycki: > On Thu, 15 Nov 2007, Oliver Neukum wrote: > > I am seeing an interrupt for an UHCI on #20 CPU1 also arriving on > > #19 CPU0, triggering the spurious interrupt detection. > > Well, if you see spurious interrupt detection triggered, then it is not a > problem with the interrupt being delivered multiple times (that's handled > silently by the interrupt dispatched), but likely the interrupt line being > deasserted too late. Does it happen frequently? If your ERR counter in > /proc/interrupts increments quite fast, then perhaps a driver does not > handle interrupts well enough for your system. Or there is noise on an > interrupt line. > > You would have to provide more information to get more accurate feedback. On irq 20, there's an UHCI, on irq 19 is an EHCI. For every interrupt on 20 there's a spurious interrupt on 19. USB devices on bus of the controller on 20 work. So I know all interrupts are seen. ERR does not increase. Interrupts for devices on the bus of the controller on 19 arrive at 19 only. As far as I can determine there are really interrupts on both CPUs on different vectors for one physical interrupt request. Regards Oliver