Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755780AbYFCKM1 (ORCPT ); Tue, 3 Jun 2008 06:12:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751950AbYFCKMQ (ORCPT ); Tue, 3 Jun 2008 06:12:16 -0400 Received: from www.tglx.de ([62.245.132.106]:43744 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751762AbYFCKMO (ORCPT ); Tue, 3 Jun 2008 06:12:14 -0400 Date: Tue, 3 Jun 2008 12:11:43 +0200 (CEST) From: Thomas Gleixner To: Olaf Dabrunz cc: Ingo Molnar , "H. Peter Anvin" , Jon Masters , Stefan Assmann , "Eric W. Biederman" , LKML Subject: Re: [PATCH 0/7] Boot IRQ quirks and rerouting In-Reply-To: <12124107071847-git-send-email-od@suse.de> Message-ID: References: <12124107071847-git-send-email-od@suse.de> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1491 Lines: 35 Olaf, On Mon, 2 Jun 2008, Olaf Dabrunz wrote: > These patches are against linux-2.6-tip, auto-x86-next. > > When IRQ lines on secondary or higher IO-APICs are masked (as done by > RT and others), many chipsets redirect IRQs on this line to the PIC, and > thereby regularly to the first IO-APIC in the system. This causes > spurious interrupts and can lead to disabled IRQ lines. > > Disabling this "boot interrupt" (as it is mostly used to supply all > IRQs to the legacy PIC during boot) is chipset-specific, and not > possible for all chips. This patchset disables the boot interrupt on > chipsets where this is possible and where we know how to do it. > > When disabling the boot interrupt is not possible, the patches tell the > IRQ code to always use the redirected interrupt line (on the first > IO-APIC) instead of the "original" line on the secondary (tertiary ...) > IO-APIC. The original line remains masked, and IRQs always appear on > the boot interrupt line on the first IO-APIC instead. Thanks for doing the research on this problem. We probably don't want to enable this unconditionally right away, so we should have a command line option which enables these quirks. Also is there any interaction with MSI ? Thanks, tglx -- 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/