From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH V3 2/7] PM / OPP: Introduce "domain-performance-state" binding to OPP nodes Date: Wed, 1 Mar 2017 11:44:02 +0530 Message-ID: <20170301061402.GE24323@vireshk-i7> References: <20170228003948.ihf4c2ppu2rf3lt2@rob-hp-laptop> <20170228065711.GD19417@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f173.google.com ([209.85.192.173]:33483 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750703AbdCAGOF (ORCPT ); Wed, 1 Mar 2017 01:14:05 -0500 Received: by mail-pf0-f173.google.com with SMTP id w189so7693819pfb.0 for ; Tue, 28 Feb 2017 22:14:05 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Rob Herring Cc: Ulf Hansson , 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 , Rajendra Nayak , "devicetree@vger.kernel.org" On 28-02-17, 09:52, Rob Herring wrote: > On Tue, Feb 28, 2017 at 9:14 AM, Ulf Hansson wrote: > > 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. An important thing here is that PM domain doesn't support such devices. i.e. a device isn't allowed to have multiple PM domains today. So a way to support such devices can be to create a virtual PM domain, that has two parents and device as its child. -- viresh