Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756030Ab3HWSiI (ORCPT ); Fri, 23 Aug 2013 14:38:08 -0400 Received: from mail-oa0-f53.google.com ([209.85.219.53]:46428 "EHLO mail-oa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755722Ab3HWSiF (ORCPT ); Fri, 23 Aug 2013 14:38:05 -0400 MIME-Version: 1.0 In-Reply-To: <52167A35.2010109@wwwdotorg.org> References: <1377092334-770-1-git-send-email-larsi@wh2.tu-dresden.de> <1507189.CRWvzVJqTV@flatron> <521548E3.6010703@wwwdotorg.org> <52167A35.2010109@wwwdotorg.org> Date: Fri, 23 Aug 2013 20:38:04 +0200 Message-ID: Subject: Re: [PATCH v2] gpio: interrupt consistency check for OF GPIO IRQs From: Linus Walleij To: Stephen Warren Cc: Tomasz Figa , Lars Poeschel , Lars Poeschel , Grant Likely , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , Mark Rutland , Ian Campbell , Kumar Gala , Pawel Moll , Javier Martinez Canillas , Enric Balletbo i Serra , Jean-Christophe PLAGNIOL-VILLARD , Santosh Shilimkar , Kevin Hilman , Balaji T K , Tony Lindgren , Jon Hunter Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1453 Lines: 36 On Thu, Aug 22, 2013 at 10:53 PM, Stephen Warren wrote: > On 08/21/2013 05:27 PM, Linus Walleij wrote: >> On Thu, Aug 22, 2013 at 1:10 AM, Stephen Warren wrote: >>>> On Wednesday 21 of August 2013 15:38:54 Lars Poeschel wrote: >> >>>>> To solve this dilemma, perform an interrupt consistency check >>>>> when adding a GPIO chip: if the chip is both gpio-controller and >>>>> interrupt-controller, walk all children of the device tree, >>> >>> It seems a little odd to solve this only for DT. What about the non-DT case? >> >> DT is the hardware configuration system that lets you request >> the same resource in two ways, i.e. it allows one and the same >> node to be both gpio-controller and interrupt-controller, and >> start handing out the same line as both GPIO and IRQ >> independently. > > Huh? What stops systems using board files and platform data from having > this issue? It can't be stopped but I consider it a bug if they do, as the proper way to handle such GPIO lines is the sequence: request_gpio(gpio); request_irq(gpio_to_irq(gpio)); But I was mainly contrasting against ACPI, where the problem appears to not exist. Yours, Linus Walleij -- 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/