Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752541AbaBSAUr (ORCPT ); Tue, 18 Feb 2014 19:20:47 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:42223 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751454AbaBSAUp (ORCPT ); Tue, 18 Feb 2014 19:20:45 -0500 Date: Tue, 18 Feb 2014 16:20:43 -0800 From: Stephen Boyd To: Lorenzo Pieralisi Cc: Borislav Petkov , "linux-kernel@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-edac@vger.kernel.org" , Mark Rutland , Kumar Gala , "devicetree@vger.kernel.org" Subject: Re: [PATCH v5 2/4] devicetree: bindings: Document Krait CPU/L1 EDAC Message-ID: <20140219002043.GE14769@codeaurora.org> References: <1389735034-21430-1-git-send-email-sboyd@codeaurora.org> <1389735034-21430-3-git-send-email-sboyd@codeaurora.org> <20140115102701.GA27314@e102568-lin.cambridge.arm.com> <20140115165623.GJ14405@codeaurora.org> <20140116013840.GA674@codeaurora.org> <20140116113332.GC25540@e102568-lin.cambridge.arm.com> <20140116180505.GA30925@codeaurora.org> <20140116183326.GG25540@e102568-lin.cambridge.arm.com> <20140116192617.GA13785@codeaurora.org> <20140117102109.GA22544@e102568-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140117102109.GA22544@e102568-lin.cambridge.arm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (Sorry, this discussion stalled due to merge window + life events) On 01/17, Lorenzo Pieralisi wrote: > On Thu, Jan 16, 2014 at 07:26:17PM +0000, Stephen Boyd wrote: > > On 01/16, Lorenzo Pieralisi wrote: > > > On Thu, Jan 16, 2014 at 06:05:05PM +0000, Stephen Boyd wrote: > > > > On 01/16, Lorenzo Pieralisi wrote: > > > > > Do we really want to do that ? I am not sure. A cpus node is supposed to > > > > > be a container node, we should not define this binding just because we > > > > > know the kernel creates a platform device for it then. > > > > > > > > This is just copying more of the ePAPR spec into this document. > > > > It just so happens that having a compatible field here allows a > > > > platform device to be created. I don't see why that's a problem. > > > > > > I do not see why you cannot define a node like pmu or arch-timer and stick > > > a compatible property in there. cpus node does not represent a device, and > > > must not be created as a platform device, that's my opinion. > > > > > > > I had what you're suggesting before in the original revision of > > this patch. Please take a look at the original patch series[1]. I > > suppose it could be tweaked slightly to still have a cache node > > for the L2 interrupt and the next-level-cache pointer from the > > CPUs. > > Ok, sorry, we are running around in circles here, basically you moved > the node to cpus according to reviews. I still think that treating cpus > as a device is not a great idea, even though I am in the same > position with C-states and probably will add C-state tables in the cpus > node. > > http://comments.gmane.org/gmane.linux.power-management.general/41012 > > I just would like to see under cpus nodes and properties that apply to > all ARM systems, and avoid defining properties (eg interrupts) that > have different meanings for different ARM cores. > > The question related to why the kernel should create a platform device > out of cpus is still open. I really do not want to block your series > for these simple issues but we have to make a decision and stick to that, > I am fine either way if we have a plan. > Do you just want a backup plan in case we don't make a platform device out of the cpus node? I believe we can always add code somewhere to create a platform device at runtime if we detect the cpus node has a compatible string equal to "qcom,krait". We could probably change this driver's module_init() to scan the DT for such a compatible string and create the platform device right there. If we get more than one interrupt in the cpus node we can add interrupt-names and then have software look for interrupts by name instead of number. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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/