Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758534AbcCVMpD (ORCPT ); Tue, 22 Mar 2016 08:45:03 -0400 Received: from mail.kernel.org ([198.145.29.136]:58866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753885AbcCVMpA (ORCPT ); Tue, 22 Mar 2016 08:45:00 -0400 MIME-Version: 1.0 In-Reply-To: <56F0C375.1030907@nvidia.com> References: <1458010724-10945-1-git-send-email-acourbot@nvidia.com> <1458010724-10945-4-git-send-email-acourbot@nvidia.com> <20160318204748.GA20243@rob-hp-laptop> <56F0C375.1030907@nvidia.com> From: Rob Herring Date: Tue, 22 Mar 2016 07:44:37 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU To: Alexandre Courbot Cc: Alexandre Courbot , Stephen Warren , Thierry Reding , "devicetree@vger.kernel.org" , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , "linux-tegra@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1709 Lines: 53 On Mon, Mar 21, 2016 at 11:00 PM, Alexandre Courbot wrote: > On 03/22/2016 10:41 AM, Rob Herring wrote: >> >> On Sun, Mar 20, 2016 at 1:55 AM, Alexandre Courbot >> wrote: >>> >>> On Sat, Mar 19, 2016 at 5:47 AM, Rob Herring wrote: >>>> >>>> On Tue, Mar 15, 2016 at 11:58:42AM +0900, Alexandre Courbot wrote: >>>>> >>>>> GM20B's definition is mostly similar to GK20A's, but requires an >>>>> additional clock. >> >> >> [...] >> >>>>> gpu@0,57000000 { >>>>> compatible = "nvidia,gk20a"; >>>>> @@ -45,3 +49,22 @@ Example: >>>>> iommus = <&mc TEGRA_SWGROUP_GPU>; >>>>> status = "disabled"; >>>>> }; >>>>> + >>>>> +Example for GM20B: >>>>> + >>>>> + gpu@0,57000000 { >>>> >>>> >>>> Drop the comma and leading zero. >>> >>> >>> Even though this is how it appears in the actual DT? >> >> >> Yes, those will need to get fixed, too. > > > Sorry, I just want to confirm that I understand why this needs to be fixed. > The parent node has #address-cells = <2>, and the practice of specifying two > cells in the node name is consistent with what I see in > http://www.devicetree.org/Device_Tree_Usage. > > However in the device tree usage example one can interpret the two cells as > being two different components of the address, whereas in our case we are > using two cells because the address is 64-bit - hence we should specify it > in the name as a single entity. Is this correct? Exactly, commas are for separating distinct fields like chip select and offset in the wiki example. A 64-bit address is a single field. The other reason to fix it is dtc is going to start warning for this. Rob