From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandra Yates Subject: Re: [PATCH] fix intel_pstate to update MSR values when changing governors Date: Tue, 17 Nov 2015 17:45:11 -0800 Message-ID: <564BD827.6030803@linux.intel.com> References: <1445043101-19079-1-git-send-email-alexandra.yates@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com ([192.55.52.115]:52537 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754240AbbKRBmN (ORCPT ); Tue, 17 Nov 2015 20:42:13 -0500 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: kristen@linux.intel.com, "linux-pm@vger.kernel.org" , root On 10/16/2015 06:15 PM, Rafael J. Wysocki wrote: > Hi, > > On Sat, Oct 17, 2015 at 2:51 AM, Alexandra Yates > wrote: >> From: root >> >> When changing from powersave to performance governors >> Intel_pstate fails to update the MSR values that reflect the >> max_perf_pct to 100%. For instance: >> >> Governor MSR max_perf_pct >> ========= ==== ============ >> Powersave 2828 100% >> Powersave 2028 80% >> Performance 2028 100% <- >> >> The arrow shows the culprit. At this point the MSR should >> reflect the max_perf_pct that is 100% that corresponds MSR 2828 >> the maximum performance for the Performance governor. >> Instead it holds back the MSR value previously set >> by the Powersave governor 2028. >> >> Signed-off-by: root > Sorry about this I sent the patch against an internal tree. Won't happen again. > It looks like you need to update your git configuration. > > More to the point, I wonder if this commit addresses the problem your seeing: > I tested only with the following patch in question and it doesn't fix the error for the MSR values on SKL. I'm resending my patch rebased to linux-pm, including a better explanation on what the error is and what is fixing. > http://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=bleeding-edge&id=51443fbf3d2cde16011b994252c8004ebcd66fb0 > >> --- >> 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 cde38c8..992dbb5 100644 >> --- a/drivers/cpufreq/intel_pstate.c >> +++ b/drivers/cpufreq/intel_pstate.c >> @@ -1239,6 +1239,8 @@ 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(); >> return 0; >> } >> >> -- > > Thanks, > Rafael > -- Thank you,