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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 34E97C433EF for ; Thu, 9 Sep 2021 11:19:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D1A66115A for ; Thu, 9 Sep 2021 11:19:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236151AbhIILUx (ORCPT ); Thu, 9 Sep 2021 07:20:53 -0400 Received: from mail-ot1-f44.google.com ([209.85.210.44]:43671 "EHLO mail-ot1-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234993AbhIILT4 (ORCPT ); Thu, 9 Sep 2021 07:19:56 -0400 Received: by mail-ot1-f44.google.com with SMTP id x10-20020a056830408a00b004f26cead745so1982469ott.10; Thu, 09 Sep 2021 04:18:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KB4OAq1FA2ibjg5GPYhy0r8vL3pcy4KSo6N7CuRv9t0=; b=rPT8Ht9djkYZO7tpf/XG4G6u4N0u3x69s3X31gq8kSp0Jezqv0AmxopmRUbJW3dg2T ZQgQNnonZ7XRVeMWkDwUMGAOlmJv/NFG9O69NNOl3ytyku0xpfwM6Zfws65a/N8a4sCG hQa2j5f7vG0eqLZilBBq4Z3zOxU58YflXG8zZf0hhgE83E3y/936SOyZKzX2zC0UySYX KSWtZ03TvtiPd+9ZYkuzWVeviGUK4mk1IVUQTNkGqonm9NIcRTTpffIIigxFEy3//zEs Ijzi1kwdGmIkhvoJKgqt4JJ2Jw0F2mikE5RiJ8IpmqPzDi2tyNnp9WcvWFGW0xknbRto KDPw== X-Gm-Message-State: AOAM530T6vh6//zPqJK2fXjlc8muUdstfF/1zXwuKetnrm0it+hPLWMc zeCfZALhfM3BifPOnPtPR1+KM9fm1XjfL+IjYtM= X-Google-Smtp-Source: ABdhPJz9VuZXyIc9RMeckXxDqTc7BW4njRZot0Sok+1ydJryCzKVqARZ0F5XmXgWRueJFJliuGfdqVBpgcb9plJweBg= X-Received: by 2002:a05:6830:34b:: with SMTP id h11mr2006848ote.319.1631186326826; Thu, 09 Sep 2021 04:18:46 -0700 (PDT) MIME-Version: 1.0 References: <20210909034802.1708-1-dsmythies@telus.net> <223a72d91cfda9b13230e4f8cd6a29f853535277.camel@linux.intel.com> In-Reply-To: <223a72d91cfda9b13230e4f8cd6a29f853535277.camel@linux.intel.com> From: "Rafael J. Wysocki" Date: Thu, 9 Sep 2021 13:18:35 +0200 Message-ID: Subject: Re: [PATCH] cpufreq: intel_pstate: Override parameters if HWP forced by BIOS To: Srinivas Pandruvada , Doug Smythies Cc: "Rafael J. Wysocki" , Len Brown , Doug Smythies , Linux Kernel Mailing List , Linux PM Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada wrote: > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > If HWP has been already been enabled by BIOS, it may be > > necessary to override some kernel command line parameters. > > Once it has been enabled it requires a reset to be disabled. > > > > Signed-off-by: Doug Smythies > > --- > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > b/drivers/cpufreq/intel_pstate.c > > index bb4549959b11..073bae5d4498 100644 > > --- a/drivers/cpufreq/intel_pstate.c > > +++ b/drivers/cpufreq/intel_pstate.c > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > */ > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > intel_pstate_hwp_is_enabled()) { > > - hwp_active++; > > + hwp_active = 1; > Why this change? I think hwp_active can be changed to bool and then it would make sense to update this line. > > hwp_mode_bdw = id->driver_data; > > intel_pstate.attr = hwp_cpufreq_attrs; > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > static int __init intel_pstate_setup(char *str) > > { > > + /* > > + * If BIOS is forcing HWP, then parameter > > + * overrides might be needed. Only print > > + * the message once, and regardless of > > + * any overrides. > > + */ > > + if(!hwp_active > This part of code is from early_param, Is it possible that > hwp_active is not 0? Well, it wouldn't matter even if it were nonzero. This check is just pointless anyway. > > && boot_cpu_has(X86_FEATURE_HWP)) > > + if(intel_pstate_hwp_is_enabled()){ This should be if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > + pr_info("HWP enabled by BIOS\n"); > > + hwp_active = 1; > > + } > > if (!str) > > return -EINVAL; > > > > - if (!strcmp(str, "disable")) > > + if (!strcmp(str, "disable") && !hwp_active) > > no_load = 1; > > - else if (!strcmp(str, "active")) > > + if (!strcmp(str, "active")) > > default_driver = &intel_pstate; > > - else if (!strcmp(str, "passive")) > > + if (!strcmp(str, "passive")) > > default_driver = &intel_cpufreq; > > Why "else if" changed to "if" ? > > > - > > - if (!strcmp(str, "no_hwp")) { > > + if (!strcmp(str, "no_hwp") && !hwp_active) { > > pr_info("HWP disabled\n"); > > no_hwp = 1; > > } >