From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D79E405C41; Fri, 15 May 2026 22:14:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778883300; cv=none; b=Kr7ywacJaM6KWWUfuD2ScIPuwRddsOtLOVWs02dolt8cQqdikQOyiA7qPTxakRx7Iik5kyU/1HzT7kuf6XKar1McdDLQIaXjolDYR4powEYoKwEZiCgo1G90WgE+155V4iscOFOzu3yHGjaCC1GkODvkt+1jyRDEyWiRMBrV8po= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778883300; c=relaxed/simple; bh=jtBOm2uPnQYFmHSs1M/Yo/0rcke+5LEHR4oPThHOhZc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rrY+1FhGWf3UfiUG1F3qZ/ATUxI0pfdvehZJBUtHwSi+/MsmHHHn0Clm17jD64sBvVxj6YQH5saYkaIUfBrsvbeEh0QJf2fd0lVvjVBcHPmy+mlhc27Lrav7ObYgxZEQMlRhcul2NOKaoRxeq9F1UgbizTIhTkUnHsVzZPG2gpE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=iiVNrNKX; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iiVNrNKX" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=1zobbfP4WB+3+tnZ3vazEKyIHxBQmbIB/DheGdu717s=; b=iiVNrNKXTsWSokzcQ919SL720G O/TkcfxKmdlMg+fgOOcgbUHgrQbfR7uNLTxklxsuXzYoI8vvvbAoT8VkSOm1dm0j46SHOdn2hhld+ 7aHSuxcdQtUXDpRpJNlJbFTceu8QKixWs/HbEQsV8QpgLY3ItQmFAIRhnC5/gDwhUXamV/2clFEyF ANaEaeRasQjB0Z4cvvu3BpWJ3vXpi3fEvkuzsfl0j18t/Zl+c+P4SAMlTaF8tTZLk0AbrzB9gtAD6 65c/FEnwS4l86rBW01G7SVI1E0NzxW9W2SCoHYayBNuLJ7dtTA9FjgreemAl2qM7J9vI4BObllToC YaVC617w==; Received: from [50.53.43.113] (helo=[192.168.254.34]) by bombadil.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wO0o2-00000009bil-0mKg; Fri, 15 May 2026 22:14:54 +0000 Message-ID: Date: Fri, 15 May 2026 15:14:52 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] cpufreq: CPPC: add autonomous mode boot parameter support To: Sumit Gupta , rafael@kernel.org, viresh.kumar@linaro.org, pierre.gondois@arm.com, ionela.voinescu@arm.com, zhenglifeng1@huawei.com, zhanjie9@hisilicon.com, corbet@lwn.net, skhan@linuxfoundation.org, mario.limonciello@amd.com, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-tegra@vger.kernel.org, treding@nvidia.com, jonathanh@nvidia.com, vsethi@nvidia.com, ksitaraman@nvidia.com, sanjayc@nvidia.com, mochs@nvidia.com, bbasu@nvidia.com References: <20260515122624.1920637-1-sumitg@nvidia.com> <20260515122624.1920637-3-sumitg@nvidia.com> Content-Language: en-US From: Randy Dunlap In-Reply-To: <20260515122624.1920637-3-sumitg@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/15/26 5:26 AM, Sumit Gupta wrote: > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 0eb64aab3685..7e4b3a8fd76f 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1048,6 +1048,22 @@ Kernel parameters > policy to use. This governor must be registered in the > kernel before the cpufreq driver probes. > > + cppc_cpufreq.auto_sel_mode= > + [CPU_FREQ] Enable ACPI CPPC autonomous performance I just noticed that we should have both CPU_FREQ and CPU_IDLE added to the legend (meanings) section at the very beginning of this file, but that doesn't have to be part of this patch. > + selection. When enabled, hardware automatically adjusts > + CPU frequency on all CPUs based on workload demands. > + In Autonomous mode, Energy Performance Preference (EPP) > + hints guide hardware toward performance (0x0) or energy > + efficiency (0xff). > + Requires ACPI CPPC autonomous selection register > + support. > + Accepts: > + performance, 1: enable auto_sel + set EPP to > + performance (0x0) > + default_epp, 2: enable auto_sel, preserve EPP value > + programmed by BIOS/firmware > + Unset: cpufreq governors are used (auto_sel disabled). -- ~Randy