Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756241Ab0FHUEZ (ORCPT ); Tue, 8 Jun 2010 16:04:25 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:42421 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755896Ab0FHUEY (ORCPT ); Tue, 8 Jun 2010 16:04:24 -0400 To: "H. Peter Anvin" Cc: Alan Cox , Jacob Pan , Alan Cox , Arjan van de Ven , LKML , Ingo Molnar , Feng Tang , Len Brown References: <1275952044-27996-1-git-send-email-jacob.jun.pan@linux.intel.com> <4C0D8F43.4070900@zytor.com> <20100608091012.034f1cca@lxorguk.ukuu.org.uk> <4C0E87BB.4050303@zytor.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: Tue, 08 Jun 2010 13:04:15 -0700 In-Reply-To: <4C0E87BB.4050303@zytor.com> (H. Peter Anvin's message of "Tue\, 08 Jun 2010 11\:11\:07 -0700") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=67.188.5.249;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 67.188.5.249 X-SA-Exim-Rcpt-To: hpa@zytor.com, len.brown@intel.com, feng.tang@intel.com, mingo@elte.hu, linux-kernel@vger.kernel.org, arjan@linux.intel.com, alan@linux.intel.com, jacob.jun.pan@linux.intel.com, alan@lxorguk.ukuu.org.uk X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa01 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"H. Peter Anvin" X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa01 1397; Body=1 Fuz1=1 Fuz2=1] * 0.1 XMSolicitRefs_0 Weightloss drug * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: [PATCH] x86/sfi: fix ioapic gsi range X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1257 Lines: 28 "H. Peter Anvin" writes: > On 06/08/2010 01:10 AM, Alan Cox wrote: >>>> You may not use a 1-1 mapping if you don't have legacy irqs. Linux >>>> irqs 0-15 are the ISA irqs you may not use those irq numbers for >> >> Linux IRQ 0 is "no IRQ assigned", except buried in certain bits of arch >> specific historical knowledge. >> >> Also calling 1-15 ISA IRQ lines is also somewhat misleading given they >> are almost certainly routing for PCI devices. "PIC IRQ routing" maybe - >> but even that is not really true on a lot of PC hardware today except by >> convention. > > Yes, but I gather IRQ/GSI 0 is an early-acquire primary timer on MRST on > Moorestown just as on PC/AT... just a different one. Hence "special" in > the same sort of way. I don't really care, personally, though. Right. I have to admit I was stunned when I realized that request_irq works and has worked for a long time with irq 0. I think that might actually be a bug. setup_irq is traditionally used for irq 0. Eric -- 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/