From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B596C43381 for ; Tue, 26 Mar 2019 11:40:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63C3520856 for ; Tue, 26 Mar 2019 11:40:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729625AbfCZLkQ (ORCPT ); Tue, 26 Mar 2019 07:40:16 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:57958 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726171AbfCZLkQ (ORCPT ); Tue, 26 Mar 2019 07:40:16 -0400 Received: from 79.184.253.239.ipv4.supernova.orange.pl (79.184.253.239) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.213) id b1acf7c466be819c; Tue, 26 Mar 2019 12:40:13 +0100 From: "Rafael J. Wysocki" To: Srinivas Pandruvada Cc: lenb@kernel.org, viresh.kumar@linaro.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, pprakash@codeaurora.org, wangxiongfeng2@huawei.com Subject: Re: [PATCH v2 0/2] Correct the processing for base_frequency Date: Tue, 26 Mar 2019 12:38:17 +0100 Message-ID: <3574470.KuU4jANTQq@aspire.rjw.lan> In-Reply-To: <20190325160440.7575-1-srinivas.pandruvada@linux.intel.com> References: <20190325160440.7575-1-srinivas.pandruvada@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, March 25, 2019 5:04:38 PM CET Srinivas Pandruvada wrote: > The base_frequency display in cpufreq sysfs for intel_pstate gets the > guaranteed ratio by reading CPPC guaranteed performance register as a > first preference before falling back to x86 MSR for Hardware P-state > Capabilities. The current code in cppc_acpi.c assumed that "guaranteed > performance register" can be an integer field, which is invalid as per > ACPI spec. So this change explicitly check for INTEGER values for > invalid BIOS/firmware and ignore. > Also guaranteed performance register field is optional and when not > present, nominal performance can be used as the guaranteed performance. > But spec calls that this is true only in non-autonomous mode. So > no change is made in cppc_acpi.c to make nominal as guaranteed in this > case to avoid dependency on autonomous and non-autonomous mode. Instead > a change is added to intel_pstate driver, which is specific to x86 to > make nominal as guaranteed when guaranteed performance field is absent > or has invalid value. > Also we are working to clarify this non-autonomous mode requirement > through ACPI standard body. > > v2: > Changes done as suggested by Rafael. > > > Srinivas Pandruvada (2): > ACPI / CPPC: Fix processing for guaranteed performance > cpufreq: intel_pstate: Also use cppc nominal_perf for base_frequency > > drivers/acpi/cppc_acpi.c | 9 +++++++-- > drivers/cpufreq/intel_pstate.c | 5 ++++- > 2 files changed, 11 insertions(+), 3 deletions(-) > > Both applied, thanks!