Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266204AbUIIVEJ (ORCPT ); Thu, 9 Sep 2004 17:04:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266169AbUIIVCH (ORCPT ); Thu, 9 Sep 2004 17:02:07 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:13834 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S266196AbUIIVAN (ORCPT ); Thu, 9 Sep 2004 17:00:13 -0400 Date: Thu, 9 Sep 2004 22:00:04 +0100 From: Russell King To: Scott Wood Cc: Arjan van de Ven , William Lee Irwin III , Ingo Molnar , Christoph Hellwig , Andrew Morton , Zwane Mwaikambo , linux-kernel@vger.kernel.org Subject: Re: [patch] generic-hardirqs-2.6.9-rc1-mm4.patch Message-ID: <20040909220004.F6434@flint.arm.linux.org.uk> Mail-Followup-To: Scott Wood , Arjan van de Ven , William Lee Irwin III , Ingo Molnar , Christoph Hellwig , Andrew Morton , Zwane Mwaikambo , linux-kernel@vger.kernel.org References: <1094652572.2800.14.camel@laptop.fenrus.com> <20040908182509.GA6009@elte.hu> <20040908211415.GA20168@elte.hu> <20040909175748.A12336@infradead.org> <20040909172401.GA28376@elte.hu> <20040909175314.GD3106@holomorphy.com> <20040909175441.GA25686@devserv.devel.redhat.com> <20040909211038.E6434@flint.arm.linux.org.uk> <20040909205153.GA1014@yoda.timesys> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20040909205153.GA1014@yoda.timesys>; from scott@timesys.com on Thu, Sep 09, 2004 at 04:51:53PM -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1454 Lines: 37 On Thu, Sep 09, 2004 at 04:51:53PM -0400, Scott Wood wrote: > On Thu, Sep 09, 2004 at 09:10:38PM +0100, Russell King wrote: > > If it uses irq_desc then ARM won't use it. irq_desc is part of the > > far-too-restrictive x86 IRQ handlign code which is unsuitable for > > ARM platforms. > > What does ARM need that irq_desc doesn't provide, and which could not > be added? IMHO, it'd be better to fix the generic code than maintain > completely separate implementations. Unfortunately, to deal with this issue would mean breaking off from planned work, so I'm not going to be in a position to do an element by element comparison of the structures for some time. Maybe I can look at it after the weekend though. However, I think if you just compare: linux/include/linux/irq.h linux/include/asm-arm/mach/irq.h you'll realise how inadequate the "generic" IRQ code is for ARM. Note that IRQ handling on ARM is a multi-level affair where we have multiple levels of interrupt controllers which need to be traversed in software. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/ 2.6 Serial core - 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/