From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT Date: Wed, 17 Jun 2015 19:03:14 +0530 Message-ID: <20150617133314.GB15153@linux> References: <263c128844f5a3c9280c8be71f6c9eb1869a5188.1433434659.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Rob Herring Cc: Stephen Boyd , Rafael Wysocki , "linaro-kernel@lists.linaro.org" , "linux-pm@vger.kernel.org" , Arnd Bergmann , Nishanth Menon , Mark Brown , Mike Turquette , Grant Likely , Olof Johansson , Sudeep Holla , "devicetree@vger.kernel.org" , Viswanath Puttagunta , Lucas Stach , Thomas Petazzoni , "linux-arm-kernel@lists.infradead.org" , Thomas Abraham , Abhilash Kesavan , Kevin Hilman , Santosh List-Id: devicetree@vger.kernel.org On 17-06-15, 08:23, Rob Herring wrote: > > + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>; > > You've made a fundamental change here in that this can now be a list > of phandles. There should be some description on what a list means > (merge the tables?, select one?). Did you miss the description I wrote few lines earlier or are you asking for something else? This is what I wrote earlier: > > +Devices may want to choose OPP tables at runtime and so can provide a list of > > +phandles here. But only *one* of them should be chosen at runtime. So, clearly only ONE of the tables should be used. > I think this needs to have a defined order and the platform should > know what that is. For example, if you read the efuses and decide you > need the "slow" table, you know to pick the first entry. Then you > don't need opp-name. Does that work for QCom? Why forcing on the order here? For example, consider a case where the platform can have four tables, A B C D. Now DT is free to pass all four or just a subset of those. Like, for some boards table B doesn't stand valid. And so it may wanna pass just A C D. And so keeping these tables in order is going to break for sure. Flexibility is probably better in this case. -- viresh From mboxrd@z Thu Jan 1 00:00:00 1970 From: viresh.kumar@linaro.org (Viresh Kumar) Date: Wed, 17 Jun 2015 19:03:14 +0530 Subject: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT In-Reply-To: References: <263c128844f5a3c9280c8be71f6c9eb1869a5188.1433434659.git.viresh.kumar@linaro.org> Message-ID: <20150617133314.GB15153@linux> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 17-06-15, 08:23, Rob Herring wrote: > > + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>; > > You've made a fundamental change here in that this can now be a list > of phandles. There should be some description on what a list means > (merge the tables?, select one?). Did you miss the description I wrote few lines earlier or are you asking for something else? This is what I wrote earlier: > > +Devices may want to choose OPP tables at runtime and so can provide a list of > > +phandles here. But only *one* of them should be chosen at runtime. So, clearly only ONE of the tables should be used. > I think this needs to have a defined order and the platform should > know what that is. For example, if you read the efuses and decide you > need the "slow" table, you know to pick the first entry. Then you > don't need opp-name. Does that work for QCom? Why forcing on the order here? For example, consider a case where the platform can have four tables, A B C D. Now DT is free to pass all four or just a subset of those. Like, for some boards table B doesn't stand valid. And so it may wanna pass just A C D. And so keeping these tables in order is going to break for sure. Flexibility is probably better in this case. -- viresh