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 v9 10/13] Documentation: amd-pstate: add amd pstate driver mode introduction
Date: Mon, 26 Dec 2022 00:34:39 +0800 [thread overview]
Message-ID: <20221225163442.2205660-11-perry.yuan@amd.com> (raw)
In-Reply-To: <20221225163442.2205660-1-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
next prev parent reply other threads:[~2022-12-25 16:36 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-25 16:34 [PATCH v9 00/13] Implement AMD Pstate EPP Driver Perry Yuan
2022-12-25 16:34 ` [PATCH v9 01/13] ACPI: CPPC: Add AMD pstate energy performance preference cppc control Perry Yuan
2023-01-05 5:31 ` Wyes Karny
2023-01-05 6:02 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 02/13] Documentation: amd-pstate: add EPP profiles introduction Perry Yuan
2023-01-04 0:29 ` Limonciello, Mario
2023-01-05 3:18 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 03/13] cpufreq: intel_pstate: use common macro definition for Energy Preference Performance(EPP) Perry Yuan
2023-01-04 0:31 ` Limonciello, Mario
2023-01-05 5:49 ` Yuan, Perry
2023-01-05 5:56 ` Mario Limonciello
2023-01-05 6:14 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 04/13] cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering Perry Yuan
2022-12-27 2:53 ` Viresh Kumar
2022-12-27 6:32 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 05/13] cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param() Perry Yuan
2023-01-04 0:32 ` Limonciello, Mario
2022-12-25 16:34 ` [PATCH v9 06/13] cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors Perry Yuan
2023-01-04 1:05 ` Limonciello, Mario
2023-01-05 6:20 ` Yuan, Perry
2023-01-06 5:22 ` Wyes Karny
2023-01-06 5:58 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 07/13] cpufreq: amd-pstate: implement amd pstate cpu online and offline callback Perry Yuan
2022-12-25 16:34 ` [PATCH v9 08/13] cpufreq: amd-pstate: implement suspend and resume callbacks Perry Yuan
2022-12-27 2:52 ` Viresh Kumar
2023-01-05 15:08 ` Yuan, Perry
2022-12-25 16:34 ` [PATCH v9 09/13] cpufreq: amd-pstate: add driver working mode switch support Perry Yuan
2023-01-04 1:06 ` Limonciello, Mario
2023-01-05 6:02 ` Wyes Karny
2023-01-05 6:57 ` Yuan, Perry
2023-01-05 7:29 ` Wyes Karny
2023-01-05 16:03 ` Wyes Karny
2023-01-06 2:52 ` Yuan, Perry
2023-01-06 3:46 ` Wyes Karny
2022-12-25 16:34 ` Perry Yuan [this message]
2022-12-25 16:34 ` [PATCH v9 11/13] Documentation: introduce amd pstate active mode kernel command line options Perry Yuan
2022-12-25 16:34 ` [PATCH v9 12/13] cpufreq: amd-pstate: convert sprintf with sysfs_emit() Perry Yuan
2022-12-25 16:34 ` [PATCH v9 13/13] Documentation: amd-pstate: introduce new global sysfs attributes Perry Yuan
2023-01-04 0:35 ` Limonciello, Mario
2023-01-05 6:21 ` Yuan, Perry
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