From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756005AbcGHTka (ORCPT ); Fri, 8 Jul 2016 15:40:30 -0400 Received: from mga03.intel.com ([134.134.136.65]:22819 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755400AbcGHTk1 (ORCPT ); Fri, 8 Jul 2016 15:40:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,331,1464678000"; d="scan'208";a="1018225314" Message-ID: <1468006747.13617.117.camel@linux.intel.com> Subject: Re: [PATCH] intel_pstate: Fix MSR_CONFIG_TDP_x addressing in core_get_max_pstate From: Srinivas Pandruvada To: Jan Kiszka , Linux Kernel Mailing List , "Rafael J. Wysocki" Cc: Kristen Carlson Accardi Date: Fri, 08 Jul 2016 12:39:07 -0700 In-Reply-To: <577FF3FC.6030004@siemens.com> References: <577FF3FC.6030004@siemens.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.3 (3.18.3-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2016-07-08 at 20:42 +0200, Jan Kiszka wrote: > If MSR_CONFIG_TDP_CONTROL is locked, we currently try to address some > MSR 0x80000648 or so. Mask out the relevant level bits 0 and 1. > > Found while running over the Jailhouse hypervisor which became upset > about this strange MSR index. > > Signed-off-by: Jan Kiszka Acked-by: Srinivas Pandruvada > --- >  drivers/cpufreq/intel_pstate.c | 2 +- >  1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/intel_pstate.c > b/drivers/cpufreq/intel_pstate.c > index 1fa1a32..1b15917 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -944,7 +944,7 @@ static int core_get_max_pstate(void) >   if (err) >   goto skip_tar; >   > - tdp_msr = MSR_CONFIG_TDP_NOMINAL + tdp_ctrl; > + tdp_msr = MSR_CONFIG_TDP_NOMINAL + (tdp_ctrl > & 0x3); >   err = rdmsrl_safe(tdp_msr, &tdp_ratio); >   if (err) >   goto skip_tar;