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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 v10 09/12] Documentation: amd-pstate: add amd pstate driver mode introduction
Date: Fri, 6 Jan 2023 14:14:17 +0800	[thread overview]
Message-ID: <20230106061420.95715-10-perry.yuan@amd.com> (raw)
In-Reply-To: <20230106061420.95715-1-perry.yuan@amd.com>

From: Perry Yuan <Perry.Yuan@amd.com>

The amd-pstate driver has two operation modes supported:
* CPPC Autonomous (active) mode
* CPPC non-autonomous (passive) mode.
active mode and passive mode can be chosen by different kernel parameters.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
---
 Documentation/admin-guide/pm/amd-pstate.rst | 26 +++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 33ab8ec8fc2f..62744dae3c5f 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -299,8 +299,30 @@ module which supports the new AMD P-States mechanism on most of the future AMD
 platforms. The AMD P-States mechanism is the more performance and energy
 efficiency frequency management method on AMD processors.
 
-Kernel Module Options for ``amd-pstate``
-=========================================
+
+AMD Pstate Driver Operation Modes
+=================================
+
+``amd_pstate`` CPPC has two operation modes: CPPC Autonomous(active) mode and
+CPPC non-autonomous(passive) mode.
+active mode and passive mode can be chosen by different kernel parameters.
+When in Autonomous mode, CPPC ignores requests done in the Desired Performance
+Target register and takes into account only the values set to the Minimum requested
+performance, Maximum requested performance, and Energy Performance Preference
+registers. When Autonomous is disabled, it only considers the Desired Performance Target.
+
+Active Mode
+------------
+
+``amd_pstate=active``
+
+This is the low-level firmware control mode which is implemented by ``amd_pstate_epp``
+driver with ``amd_pstate=active`` passed to the kernel in the command line.
+In this mode, ``amd_pstate_epp`` 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 according to the power supply and thermal, core voltage and some other
+hardware conditions.
 
 Passive Mode
 ------------
-- 
2.34.1


  parent reply	other threads:[~2023-01-06  6:16 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-06  6:14 [PATCH v10 00/12] Implement AMD Pstate EPP Driver Perry Yuan
2023-01-06  6:14 ` [PATCH v10 01/12] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2023-01-17 11:10   ` Huang Rui
2023-01-06  6:14 ` [PATCH v10 02/12] Documentation: amd-pstate: add EPP profiles introduction Perry Yuan
2023-01-17 11:45   ` Huang Rui
2023-01-06  6:14 ` [PATCH v10 03/12] cpufreq: intel_pstate: use common macro definition for Energy Preference Performance(EPP) Perry Yuan
2023-01-06  9:38   ` kernel test robot
2023-01-06 10:19   ` kernel test robot
2023-01-06  6:14 ` [PATCH v10 04/12] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() Perry Yuan
2023-01-17 11:57   ` Huang Rui
2023-01-06  6:14 ` [PATCH v10 05/12] cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors Perry Yuan
2023-01-06 11:19   ` Wyes Karny
2023-01-10 15:21     ` Yuan, Perry
2023-01-10 18:15   ` kernel test robot
2023-01-17 13:34   ` Huang Rui
2023-01-06  6:14 ` [PATCH v10 06/12] cpufreq: amd-pstate: implement amd pstate cpu online and offline callback Perry Yuan
2023-01-06  6:14 ` [PATCH v10 07/12] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2023-01-06  6:14 ` [PATCH v10 08/12] cpufreq: amd-pstate: add driver working mode switch support Perry Yuan
2023-01-17 13:56   ` Huang Rui
2023-01-18  6:34     ` Wyes Karny
2023-01-18  7:27       ` Yuan, Perry
2023-01-06  6:14 ` Perry Yuan [this message]
2023-01-06  6:14 ` [PATCH v10 10/12] Documentation: introduce amd pstate active mode kernel command line options Perry Yuan
2023-01-06  6:14 ` [PATCH v10 11/12] cpufreq: amd-pstate: convert sprintf with sysfs_emit() Perry Yuan
2023-01-06  6:14 ` [PATCH v10 12/12] Documentation: amd-pstate: introduce new global sysfs attributes Perry Yuan
2023-01-17 14:11   ` Huang Rui
2023-01-10 18:00 ` [PATCH v10 00/12] Implement AMD Pstate EPP Driver Wyes Karny
2023-01-17 14:03 ` Huang Rui

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