From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754011AbdCBDl2 (ORCPT ); Wed, 1 Mar 2017 22:41:28 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:45218 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753936AbdCBDlV (ORCPT ); Wed, 1 Mar 2017 22:41:21 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E535360D57 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=rnayak@codeaurora.org Message-ID: <58B791E9.4000505@codeaurora.org> Date: Thu, 02 Mar 2017 09:00:49 +0530 From: Rajendra Nayak User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Rob Herring CC: Ulf Hansson , Viresh Kumar , Rafael Wysocki , Kevin Hilman , Viresh Kumar , Nishanth Menon , Stephen Boyd , "linaro-kernel@lists.linaro.org" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Vincent Guittot , Lina Iyer , "devicetree@vger.kernel.org" , Jon Hunter Subject: Re: [PATCH V3 2/7] PM / OPP: Introduce "domain-performance-state" binding to OPP nodes References: <20170228003948.ihf4c2ppu2rf3lt2@rob-hp-laptop> <20170228065711.GD19417@vireshk-i7> <58B669DD.5010309@codeaurora.org> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/02/2017 04:43 AM, Rob Herring wrote: > On Wed, Mar 1, 2017 at 12:27 AM, Rajendra Nayak wrote: >> >> >> On 02/28/2017 09:22 PM, Rob Herring wrote: >>> On Tue, Feb 28, 2017 at 9:14 AM, Ulf Hansson wrote: >>>> [...] >>>> >>>>>> ---> Parent domain-2 (Contains Perfomance states) >>>>>> | >>>>>> | >>>>>> C.) DeviceX ---> Parent-domain-1 | >>>>>> | >>>>>> | >>>>>> ---> Parent domain-3 (Contains Perfomance states) >>>>> >>>>> I'm a bit confused. How does a domain have 2 parent domains? >>>> >>>> This comes from the early design of the generic PM domain, thus I >>>> assume we have some HW with such complex PM topology. However, I don't >>>> know if it is actually being used. >>>> >>>> Moreover, the corresponding DT bindings for "power-domains" parents, >>>> can easily be extended to cover more than one parent. See more in >>>> Documentation/devicetree/bindings/power/power_domain.txt >>> >>> I could easily see device having 2 power domains. For example a cpu >>> may have separate domains for RAM/caches and logic. And nesting of >> >> yet the bindings for power-domains (for consumer devices) only allows for >> one powerdomain to be associated with a device. > > There's nothing in the binding only allowing that. If that was true, > then #powerdomain-cells would be pointless Is't #powerdomain-cells a powerdomain provider property? and used to specify if a powerdomain provider supports providing 1 or many powerdomains? I was talking about the power domain consumer property. Looking at Documentation/devicetree/bindings/power/power_domain.txt.. ==PM domain consumers== Required properties: - power-domains : A phandle and PM domain specifier as defined by bindings of the power controller specified by phandle. It clearly says 'A phandle'. If there was a way to specify multiple power-domains for a consumer device should it not be saying a list of phandles? Like we do for clocks and regulators? > as the property size would > tell you the number of cells. Now it may be that we simply don't have > any cases with more than 1. Hopefully that's not because bindings are > working around PM domain limitations/requirements. > > Rob > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation