From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko =?ISO-8859-1?Q?St=FCbner?= Subject: Re: cpufreq(-dt) with two clocks but one regulator Date: Tue, 19 Sep 2017 11:19:45 +0200 Message-ID: <2997079.BKPG7M6LVv@diego> References: <1515316.mHJbnBRRvK@phil> <2224473.GjtbWfbYHk@phil> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from gloria.sntech.de ([95.129.55.99]:32792 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750895AbdISJT4 (ORCPT ); Tue, 19 Sep 2017 05:19:56 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Doug Anderson Cc: Viresh Kumar , "open list:ARM/Rockchip SoC..." , Klaus Goger , Vincent Guittot , "linux-pm@vger.kernel.org" Hi Doug, Am Montag, 18. September 2017, 16:37:56 CEST schrieb Doug Anderson: > On Mon, Sep 18, 2017 at 3:40 PM, Heiko Stuebner wrote: > > Current submitted OPPs can be found at > > https://patchwork.kernel.org/patch/9908519/ > > > > There were still issues with higher frequencies, so they don't list the > > 1.2 or 1.5GHz yet. > > > > But opp sets pretty tight constraints. I.e. OPPs have of course one > > preferred voltage, so you end up with u_volt_min = u_volt_max for each > > operating point, thus the regulator also gets set in this way, removing > > any > > intersection and thus making the regulator framework fail to set a voltage > > for one of the clusters. > > > > So for example, you have one cluster running at 600MHz@0.95V and the > > other cluster running at 1008MHz@1.05V this results in regulator > > constraints being > > > > 0.95V-0.95V > > > > and > > > > 1.05V-1.05V > > > > thus no intersection and whoever comes second looses. > > (Untested) Can't you change the opp table and use the fancier > operating point descriptions that give ? funny, that I never noticed that opps are also specified for (target, min, max) values. Thanks for pointing me to the right direction and this seems to actually work. Although I noticed that obviously the max value needs to always be the global maximum (1125000 here) for both opp tables, to make the regulator framework happy. > In theory the above is a more proper hardware description: AKA you're > describing that it's OK to use the higher voltage even at lower > operating points. Thanks Heiko