From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Date: Tue, 01 Mar 2011 11:43:33 +0000 Subject: Re: [PATCH 3/8] Add a mfd IPUv3 driver Message-Id: <201103011243.33765.arnd@arndb.de> List-Id: References: <1298887229-7987-1-git-send-email-s.hauer@pengutronix.de> <201103011127.51605.arnd@arndb.de> <20110301111220.GN29521@pengutronix.de> In-Reply-To: <20110301111220.GN29521@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Tuesday 01 March 2011, Sascha Hauer wrote: > > Taking one step back from this, have you considered making this > > a regular interrupt controller? That would make the client drivers > > more standard -- you could define the interrupt numbers as resources > > of a platform device or in the device tree, for instance. > > The cost might be more complex code, e.g. when a device requires > > many interrupts, but I think it will be at least as efficient > > at run-time, and less surprising for readers and authors of > > client drivers. > > I thought about this, but hesitated to increase NR_IRQS by 463. Do you > think we should do this instead? I think there is a plan to virtualize the interrupt numbers on ARM, and in that case NR_IRQS becomes rather meaningless. I don't know exactly how far that effort has come. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Tue, 1 Mar 2011 12:43:33 +0100 Subject: [PATCH 3/8] Add a mfd IPUv3 driver In-Reply-To: <20110301111220.GN29521@pengutronix.de> References: <1298887229-7987-1-git-send-email-s.hauer@pengutronix.de> <201103011127.51605.arnd@arndb.de> <20110301111220.GN29521@pengutronix.de> Message-ID: <201103011243.33765.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tuesday 01 March 2011, Sascha Hauer wrote: > > Taking one step back from this, have you considered making this > > a regular interrupt controller? That would make the client drivers > > more standard -- you could define the interrupt numbers as resources > > of a platform device or in the device tree, for instance. > > The cost might be more complex code, e.g. when a device requires > > many interrupts, but I think it will be at least as efficient > > at run-time, and less surprising for readers and authors of > > client drivers. > > I thought about this, but hesitated to increase NR_IRQS by 463. Do you > think we should do this instead? I think there is a plan to virtualize the interrupt numbers on ARM, and in that case NR_IRQS becomes rather meaningless. I don't know exactly how far that effort has come. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756255Ab1CALni (ORCPT ); Tue, 1 Mar 2011 06:43:38 -0500 Received: from moutng.kundenserver.de ([212.227.17.8]:50756 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756167Ab1CALng (ORCPT ); Tue, 1 Mar 2011 06:43:36 -0500 From: Arnd Bergmann To: Sascha Hauer Subject: Re: [PATCH 3/8] Add a mfd IPUv3 driver Date: Tue, 1 Mar 2011 12:43:33 +0100 User-Agent: KMail/1.12.2 (Linux/2.6.31-22-generic; KDE/4.3.2; x86_64; ; ) Cc: linux-arm-kernel@lists.infradead.org, Paul Mundt , linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, Samuel Ortiz , Alan Cox , Thomas Gleixner References: <1298887229-7987-1-git-send-email-s.hauer@pengutronix.de> <201103011127.51605.arnd@arndb.de> <20110301111220.GN29521@pengutronix.de> In-Reply-To: <20110301111220.GN29521@pengutronix.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201103011243.33765.arnd@arndb.de> X-Provags-ID: V02:K0:fZRPXftdgsEIaA3+5+vEYgvnSN4Y9h1PMtTnMGP21g3 Gk7vww/iQWLWHWn9ZW8+hkg0+yJ1iZwD7NuQhfREDQKNU4MFdc Lyz49Y6vXUrWsv53cmB7OJ88WKSdljxAHcA2HA3hkOy2WHdzQX wYEhQHo48aot0BP/Ih++20bjqFcQwaEOK8+/0i94pGKc05P6PX DmLfNGxGpI8MTdG2k+0cw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 01 March 2011, Sascha Hauer wrote: > > Taking one step back from this, have you considered making this > > a regular interrupt controller? That would make the client drivers > > more standard -- you could define the interrupt numbers as resources > > of a platform device or in the device tree, for instance. > > The cost might be more complex code, e.g. when a device requires > > many interrupts, but I think it will be at least as efficient > > at run-time, and less surprising for readers and authors of > > client drivers. > > I thought about this, but hesitated to increase NR_IRQS by 463. Do you > think we should do this instead? I think there is a plan to virtualize the interrupt numbers on ARM, and in that case NR_IRQS becomes rather meaningless. I don't know exactly how far that effort has come. Arnd