From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753937AbbKXQHW (ORCPT ); Tue, 24 Nov 2015 11:07:22 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:64831 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753030AbbKXQHU (ORCPT ); Tue, 24 Nov 2015 11:07:20 -0500 From: "Rafael J. Wysocki" To: Srinivas Pandruvada Cc: "Rafael J. Wysocki" , Alexandra Yates , Len Brown , Viresh Kumar , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List Subject: Re: [PATCH V3] SKL intel_pstate update MSR values when changing governors Date: Tue, 24 Nov 2015 17:36:59 +0100 Message-ID: <1471027.NasRT9McKq@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.1.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1448380662.3070.3.camel@linux.intel.com> References: <1447887520-10399-1-git-send-email-alexandra.yates@linux.intel.com> <8282537.nh6Mqkv7tq@vostro.rjw.lan> <1448380662.3070.3.camel@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, November 24, 2015 07:57:42 AM Srinivas Pandruvada wrote: > On Tue, 2015-11-24 at 15:28 +0100, Rafael J. Wysocki wrote: > > On Monday, November 23, 2015 05:17:36 PM Srinivas Pandruvada wrote: > > > On Tue, 2015-11-24 at 02:09 +0100, Rafael J. Wysocki wrote: > > > > Hi, > > > > > > > > On Sat, Nov 21, 2015 at 1:16 AM, Srinivas Pandruvada > > > > wrote: > > > > > > > > > [cut] > > > > > > > > > > > > For more information on the MSR values for SKL please visit > > > > > > ISDM under Managing HWP. > > > > > > > > > > > > Signed-off-by: Alexandra Yates < > > > > > > alexandra.yates@linux.intel.com> > > > > > > > > > > Acked-by: Srinivas Pandruvada < > > > > > srinivas.pandruvada@linux.intel.com> > > > > > > > > > > > > --- > > > > > > drivers/cpufreq/intel_pstate.c | 2 ++ > > > > > > 1 file changed, 2 insertions(+) > > > > > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > > > b/drivers/cpufreq/intel_pstate.c > > > > > > index 2e31d09..0eeb7da 100644 > > > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > > > @@ -1242,6 +1242,8 @@ static int > > > > > > intel_pstate_set_policy(struct > > > > > > cpufreq_policy *policy) > > > > > > policy->max >= policy->cpuinfo.max_freq) { > > > > > > pr_debug("intel_pstate: set performance\n"); > > > > > > limits = &performance_limits; > > > > > > + if (hwp_active) > > > > > > + intel_pstate_hwp_set(); > > > > > > > > Honestly, I'm not really sure how this is matching the changelog. > > > > > > > > What it does is to ensure that the correct limits are used when > > > > in the > > > > HWP mode too as far as I can say. Is my understanding correct > > > > here? > > > Yes. > > > > OK > > > > But if we make the "performance" limits take effect here, it will > > effectively > > make HWP use min = max = 100%, right? Is that what we want to happen > > here? > Yes. intel_pstate_hwp_set() uses limits->min_perf_pct and limits > ->max_perf_pct to set HWP limits. Here these will be set to 100%. OK, so that's the intended behavior of "performance" in the HWP case, right? I'll apply this patch, but I'm going to write a new changelog for it, then. Thanks, Rafael