Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755419Ab1CVLRZ (ORCPT ); Tue, 22 Mar 2011 07:17:25 -0400 Received: from www.linutronix.de ([62.245.132.108]:39661 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755337Ab1CVLRY (ORCPT ); Tue, 22 Mar 2011 07:17:24 -0400 Date: Tue, 22 Mar 2011 12:17:20 +0100 (CET) From: Thomas Gleixner To: Esben Haabendal cc: Esben Haabendal , linux-kernel@vger.kernel.org, grant.likely@secretlab.ca Subject: Re: [PATCH] Support IRQ_NOAUTOEN flag in set_irq_chained_handler() In-Reply-To: <87hbavv83c.fsf@eha.doredevelopment.dk> Message-ID: References: <1300435389-11048-1-git-send-email-eha@doredevelopment.dk> <87hbavv83c.fsf@eha.doredevelopment.dk> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1858 Lines: 50 On Tue, 22 Mar 2011, Esben Haabendal wrote: > Thomas Gleixner writes: > > > On Fri, 18 Mar 2011, eha@doredevelopment.dk wrote: > > > >> From: Esben Haabendal > >> > >> Handle IRQ_NOAUTOEN in __set_irq_handler() (ie. for > >> set_irq_chained_handler()) instead of just silently ignoring it, and in > >> the same way as is done in __setup_irq() (ie. request_irq()). > >> > >> This give a more consistent interface, and also adheres better to > >> the rule of least surprise. > > > > Well, that might be less surprising for you, but you will be surprised > > that such a change would be a real big surprise for all users of > > chained handlers in arch/arm. They simply would not work anymore. > > How is that? I don't see any use of IRQ_NOAUTOEN flag in arch/arm at > all. Is there some other way that IRQ_NOAUTOEN get's enabled in > arch/arm? Or is my patch broken in some way that it does change irq > handler setup when IRQ_NOAUTOEN is not set? Ooops, sorry. I had it somewhere in the back of my memory that ARM marked all interrupts IRQ_NOAUTOEN by default. Confused that with NOPROBE. > The idea of the patch is that it will do exactly the same as > before, unless you specifically set IRQ_NOAUTOEN before calling > set_irq_chained_handler... I understand the patch :) > > So we _cannot_ change the semantics here. All we can do is document > > it. > > With the current semantics, how are one supposed to be able use > set_irq_chained_handler without having the handler enabled immediately? Not at all. Why do you want to do that ? 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/