From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [Discussion] Performance levels of power domains Date: Thu, 27 Oct 2016 09:16:38 +0530 Message-ID: <20161027034638.GA10423@vireshk-i7> References: <7hvawfq6kh.fsf@baylibre.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f172.google.com ([209.85.192.172]:36747 "EHLO mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932887AbcJ0Dqm (ORCPT ); Wed, 26 Oct 2016 23:46:42 -0400 Received: by mail-pf0-f172.google.com with SMTP id e6so8616054pfk.3 for ; Wed, 26 Oct 2016 20:46:41 -0700 (PDT) Content-Disposition: inline In-Reply-To: <7hvawfq6kh.fsf@baylibre.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Kevin Hilman Cc: "linux-pm@vger.kernel.org" , "Rafael J. Wysocki" , Vincent Guittot , Ulf Hansson , Michael Turquette , Stephen Boyd , "Nayak, Rajendra" , Georgi Djakov , Lists linaro-kernel , Mark Brown On 26-10-16, 12:00, Kevin Hilman wrote: > Yes. As I've suggested to qcom/linaro folks (off-list discussions), I No one told me this story :) > think extending genpd to handle performance states is a logical > extension. Otherwise, you will be (re)inventing something that looks an > awful lot like genpd anyways. I completely agree. Runtime PM and genpd look to be the perfect placeholder for such stuff. I actually tried to convince Ulf yesterday on this and he wasn't sure if it will ever get accepted upstream and that's when I started this thread :) > The other related framework is per-device PM QoS which could be used to > set constraints on specific devices, and the genpd governors would then > be responsible for looking at the constraints and changing states as > needed. I am not sure if genpd governors are also background governors like cpufreq, but we need to make sure that the voltage is raised after the function requesting a change returns, so that the clk rate can be increased then. -- viresh