From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v3] gpio: interrupt consistency check for OF GPIO IRQs Date: Tue, 03 Sep 2013 11:22:23 -0600 Message-ID: <52261ACF.30504@wwwdotorg.org> References: <1377526030-32024-1-git-send-email-larsi@wh2.tu-dresden.de> <521D0964.2080209@wwwdotorg.org> <5220F849.8030909@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-gpio-owner@vger.kernel.org To: anish singh Cc: Linus Walleij , 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 , Tomasz Figa , Javier Martinez Canillas , Enric Balletbo i Serra , Jean-Christophe PLAGNIOL-VILLARD , Santosh Shilimkar , Kevin Hilman , Balaji T K , Tony Lindgren , Jon Hunter List-Id: devicetree@vger.kernel.org On 08/31/2013 09:32 AM, anish singh wrote: > On Sat, Aug 31, 2013 at 1:23 AM, Stephen Warren > wrote: > I still haven't seen an answer to why we really care about this; how > many times has code actually allocated the same GPIO/IRQ when it > shouldn't, in a way that it wasn't detectable by some other mechanism, > i.e. the feature just not working? Why are we even trying to solve this > issue? I'm not totally convinced it even makes sense to try and > solve it. > > > Probably this issue(same gpio/irq being used by multiple drivers) is > very rare > but debugging it is bit difficult. Really? It's easy to just look in /proc/interrupts and /sys/kernel/debug/gpio. > This generally happens when we are working > on latest revised boards where latest gpio number of some driver > conflicts with the some other driver. At least in the DT case, which is all that this patch solves, the DT is describing the HW GPIO/IRQ numbers, so the Linux GPIO numbers are irrelevant; everything is expressed as raw HW numbers, which are quite easy to check.