Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Perry Yuan <perry.yuan@amd.com>
To:     <rafael.j.wysocki@intel.com>, <Mario.Limonciello@amd.com>,
        <ray.huang@amd.com>, <viresh.kumar@linaro.org>
CC:     <Deepak.Sharma@amd.com>, <Nathan.Fontenot@amd.com>,
        <Alexander.Deucher@amd.com>, <Shimmer.Huang@amd.com>,
        <Xiaojian.Du@amd.com>, <Li.Meng@amd.com>, <wyes.karny@amd.com>,
        <linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v7 11/13] Documentation: introduce amd pstate active mode kernel command line options
Date:   Thu, 8 Dec 2022 19:18:50 +0800
Message-ID: <20221208111852.386731-12-perry.yuan@amd.com>
In-Reply-To: <20221208111852.386731-1-perry.yuan@amd.com>
References: <20221208111852.386731-1-perry.yuan@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Dec 2022 11:20:32.5298
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 5ed8645f-9d4b-418c-e5f9-08dad90e3873
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT037.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB5877
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

AMD Pstate driver support another firmware based autonomous mode
with "amd_pstate=active" added to the kernel command line.
In autonomous mode SMU firmware decides frequencies at 1 ms timescale
based on workload utilization, usage in other IPs, infrastructure
limits such as power, thermals and so on.

Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 42af9ca0127e..73a02816f6f8 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6970,3 +6970,10 @@
 			  management firmware translates the requests into actual
 			  hardware states (core frequency, data fabric and memory
 			  clocks etc.)
+			active
+			  Use amd_pstate_epp driver instance as the scaling driver,
+			  driver provides a hint to the hardware if software wants
+			  to bias toward performance (0x0) or energy efficiency (0xff)
+			  to the CPPC firmware. then CPPC power algorithm will
+			  calculate the runtime workload and adjust the realtime cores
+			  frequency.
-- 
2.34.1