From patchwork Fri Dec 5 09:40:53 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ethan zhao X-Patchwork-Id: 5442991 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 444679F1D4 for ; Fri, 5 Dec 2014 09:41:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 610482035C for ; Fri, 5 Dec 2014 09:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED6E120353 for ; Fri, 5 Dec 2014 09:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752413AbaLEJlH (ORCPT ); Fri, 5 Dec 2014 04:41:07 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:22749 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751232AbaLEJlE (ORCPT ); Fri, 5 Dec 2014 04:41:04 -0500 Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id sB59er37023449 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 5 Dec 2014 09:40:53 GMT Received: from aserz7022.oracle.com (aserz7022.oracle.com [141.146.126.231]) by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id sB59epxC029040 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 5 Dec 2014 09:40:52 GMT Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserz7022.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id sB59epPx029034; Fri, 5 Dec 2014 09:40:51 GMT Received: from localhost.localdomain.com (/10.182.70.25) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 05 Dec 2014 01:40:51 -0800 From: Ethan Zhao To: dirk.j.brandewie@intel.com, kristen@linux.intel.com, linda.knippers@hp.com, viresh.kumar@linaro.org, rjw@rjwysocki.net, corbet@lwn.net Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, ethan.kernel@gmail.com, alexey.kodanev@oracle.com, Ethan Zhao Subject: [PATCH 2/2 V8] intel_pstate: add kernel parameter to force loading. Date: Fri, 5 Dec 2014 18:40:53 +0900 Message-Id: <1417772453-22483-1-git-send-email-ethan.zhao@oracle.com> X-Mailer: git-send-email 1.8.3.1 X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP To force loading on Oracle Sun X86 servers, provide one kernel command line parameter intel_pstate = force For those who be aware of the risk of no power capping capabily working and try to get better performance with this driver. Signed-off-by: Ethan Zhao Tested-by: Alexey Kodanev --- v2: change to hardware vendor specific naming parameter. v4: refine code and doc. v5&v6: fix a typo in doc. v7: change enum PCC to PPC. v8: change the name of kernel command line parameter to generic one. Documentation/kernel-parameters.txt | 5 +++++ drivers/cpufreq/intel_pstate.c | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 479f332..7d0983e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1446,6 +1446,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. disable Do not enable intel_pstate as the default scaling driver for the supported processors + force + Enable intel_pstate on systems where it may cause problems to + happen due to conflicts with platform firmware attempting to + drive P-states by itself in certain situations (for thermal + control or power capping in general or other purposes). intremap= [X86-64, Intel-IOMMU] on enable Interrupt Remapping (default) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1bb62ca..2654e13 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -866,6 +866,7 @@ static struct cpufreq_driver intel_pstate_driver = { }; static int __initdata no_load; +static unsigned int force_load; static int intel_pstate_msrs_not_valid(void) { @@ -1003,7 +1004,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void) case PSS: return intel_pstate_no_acpi_pss(); case PPC: - return intel_pstate_has_acpi_ppc(); + return intel_pstate_has_acpi_ppc() && + (!force_load); } } @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str) if (!strcmp(str, "disable")) no_load = 1; + if (!strcmp(str, "force")) + force_load = 1; return 0; } early_param("intel_pstate", intel_pstate_setup);