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Shenoy" To: "Mario Limonciello (AMD)" Cc: Perry Yuan , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "open list:CPU FREQUENCY SCALING FRAMEWORK" Subject: Re: [PATCH v6 2/5] cpufreq/amd-pstate: add kernel command line to override dynamic epp Message-ID: References: <20260329203811.2590633-1-superm1@kernel.org> <20260329203811.2590633-3-superm1@kernel.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260329203811.2590633-3-superm1@kernel.org> X-ClientProxiedBy: MAXPR01CA0110.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a00:5d::28) To DS7PR12MB8252.namprd12.prod.outlook.com (2603:10b6:8:ee::7) Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB8252:EE_|SJ0PR12MB5610:EE_ X-MS-Office365-Filtering-Correlation-Id: f61cbc5e-7e0e-4134-ba6b-08de8f472b96 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|18002099003|56012099003|22082099003; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?7ITK8EJ0+fHtSUgk07dehSWl9tHEidkIg/qISRcmENAmWlW0KSJOh6Kx/8f6?= =?us-ascii?Q?3RFToek8cKf1zbDI1kStd3dOmh9jQTN6F0pa3W/d+5fYawGDni5YltdbbmCP?= =?us-ascii?Q?dxkyuLiMUN6Ex1GxsziJg5cdjFBGUbwP/LHoqq1isbKB012TvYr7tzMTnfhC?= =?us-ascii?Q?hqbxoTMA/yp6NMaWFBcEkP71EfOWPNjQdpi5NgpuxzBbHJIAR9TFmkmbRT33?= =?us-ascii?Q?gjs4SgcHiXS+o9Hj77XbfQaYoPlmfOcM7lrV07uPFyEVkB6N6QVRFaBGHyx9?= =?us-ascii?Q?iRM7SmBoX1SaOf+eP6KvY5arXJQkT80jQGcLI+vhLurndNyBagRJbXShFz//?= =?us-ascii?Q?5wkGpMzCRrRhFvidCsbh1b2TPrndJgBH4NrLl7MN4F/T27kJp4qZO5dJm2DN?= =?us-ascii?Q?gsxhLeWHpFmkCVKNgzTY7JcR1vwY9cVTF7KaYBCb1Q7VXbh6NCysHH1WPCMJ?= =?us-ascii?Q?D1Fe+kqGHeN/HiFgHw5JbD8xKQ4Rou3Y7TsQ1l2dTdX29cqf3Fsu6CBQoYQR?= =?us-ascii?Q?DQt3hEnQiV9kf+bSiJfwq3/TicQ4D5FUAzf5nh7lxo31aHOZOCckXNUkM6J2?= =?us-ascii?Q?KV5V9RVhtb6a8lHpZahiN4PrE+C2v0PSHzJvhn+ESIz9fTFh4SQ922LjHS6O?= =?us-ascii?Q?vrwvhrfp4RxK9J7z1tmeQM7o4XaWzXRtLDgaW8ZdLg8rMZ5xa+H2wxq4LV4h?= =?us-ascii?Q?IFBVdjdh0xyNxQINwjITfhkHAD/6VG9wMCsodm0JBPNGHzhxccJEbP5G1Scg?= =?us-ascii?Q?knEPgwnVeIVY3w2LoAFFrtFnuuXmmimakWe6zv+AEPuydPTdfLZF0Vd1Wmk9?= =?us-ascii?Q?jX0UrOdERyhls+5OwlmwRYzzRLLQeTWGOmSxGDEeEG2IALgN1FACZ90ukT/U?= =?us-ascii?Q?eQbvHdSOX7ue083+6fS3yPJptlgH40wz3+uucTzmuRjcDf86wXlI+paZEB0Z?= =?us-ascii?Q?ki1eLw1h52pIscCDu1JeT8KVuQ6qL9Fk6SdU7SXf9UnHkY6V8JQHfzjkCOLH?= =?us-ascii?Q?6jXgCHOAsWW2s7Nw/FUcx9qUNbaE8CaJFwLjSYZT32k9+/MgUNdaM86vevPE?= =?us-ascii?Q?KQp/XEn8sVjVXUvrAGM88dfGvphFevQidrtMl3cDKEVkYM8QjTaoSXDRQDUX?= =?us-ascii?Q?LUXceOZHVDK4n0BB8PuQUlItYNDwWLUnhGJuX1mGqaLkdb75LBNbApATJ9xP?= =?us-ascii?Q?Aj5LPbrAXyYKfWMbJ/vzA3TxoXugJqmINhNC2qWySeVsSSVniLe9HZ+1v7IX?= =?us-ascii?Q?R/pcxMCrNlAsamPEd1WL1vKncl74WwYb6pdrJO4YZfLJscbyI4Jk0kRhppHD?= =?us-ascii?Q?HsE6JUXTEFIyIKo6zaDKKbHdkr/jDCE1Y1sLwzZ0V+/d9f9rgZoa9neLqfjr?= =?us-ascii?Q?NrYceYKPvSHB7UKeTC9ltdJmgXEQQv3Xf5kq5+mlrIfqZd3/9pOoVPlpLGcj?= =?us-ascii?Q?q2VjTOBCepOLEylSExTouYoMbX2rD5Z5c/7QAUaV0KLggKSo4MsJMYjL+lAA?= =?us-ascii?Q?d/uloITzcbDZVmmqosJPyTMhr6bUd2kE1MqHSr71NrY8RX3rDKFpbOv+RvEh?= =?us-ascii?Q?U5ppH0s3nho+ZWzs/zkYC+w5dM/7GnnTxoC3n4zu9uGnTzpquJBrkqvs/sTX?= =?us-ascii?Q?i7YNKGvskQwRUlmBGUu7d1/M052NdTG2NDtfMmGJWqv1quuPz1tlpa3/2VwJ?= =?us-ascii?Q?IBLDMmtKqQ2CWLsZZmAmUDkxl8nowhpu75srP5IvVqZnCQyA4GvGRdWZsgwa?= =?us-ascii?Q?B3fywOcGDg=3D=3D?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: f61cbc5e-7e0e-4134-ba6b-08de8f472b96 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB8252.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Mar 2026 17:01:37.4265 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: kXjXaWNfnBuATr58PC6k6SpDWstghnKX30LHGfzrEByfZYmQnnWoxFkzJv9+kriKbutO5/7EMUr3TVn5K2ftig== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB5610 Hello Mario, On Sun, Mar 29, 2026 at 03:38:08PM -0500, Mario Limonciello (AMD) wrote: > Add `amd_dynamic_epp=enable` and `amd_dynamic_epp=disable` to override > the kernel configuration option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP` > locally. > > Signed-off-by: Mario Limonciello (AMD) This looks good to me. Reviewed-by: Gautham R. Shenoy -- Thanks and Regards gautham. > --- > v5->v6: > * Fix the amd_dynamic_epp kernel parameter name in amd-pstate.rst > --- > Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ > Documentation/admin-guide/pm/amd-pstate.rst | 7 +++++++ > drivers/cpufreq/amd-pstate.c | 11 +++++++++++ > 3 files changed, 25 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 03a550630644f..9552819051cd8 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -493,6 +493,13 @@ Kernel parameters > disable > Disable amd-pstate preferred core. > > + amd_dynamic_epp= > + [X86] > + disable > + Disable amd-pstate dynamic EPP. > + enable > + Enable amd-pstate dynamic EPP. > + > amijoy.map= [HW,JOY] Amiga joystick support > Map of devices attached to JOY0DAT and JOY1DAT > Format: , > diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst > index 0e4355fe13558..210207d301aa5 100644 > --- a/Documentation/admin-guide/pm/amd-pstate.rst > +++ b/Documentation/admin-guide/pm/amd-pstate.rst > @@ -474,6 +474,13 @@ For systems that support ``amd-pstate`` preferred core, the core rankings will > always be advertised by the platform. But OS can choose to ignore that via the > kernel parameter ``amd_prefcore=disable``. > > +``amd_dynamic_epp`` > + > +When AMD pstate is in auto mode, dynamic EPP will control whether the kernel > +autonomously changes the EPP mode. The default is configured by > +``CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`` but can be explicitly enabled with > +``amd_dynamic_epp=enable`` or disabled with ``amd_dynamic_epp=disable``. > + > User Space Interface in ``sysfs`` - General > =========================================== > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index 2e3fb1fd280a0..e96f1da5c7b38 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -2224,8 +2224,19 @@ static int __init amd_prefcore_param(char *str) > return 0; > } > > +static int __init amd_dynamic_epp_param(char *str) > +{ > + if (!strcmp(str, "disable")) > + dynamic_epp = false; > + if (!strcmp(str, "enable")) > + dynamic_epp = true; > + > + return 0; > +} > + > early_param("amd_pstate", amd_pstate_param); > early_param("amd_prefcore", amd_prefcore_param); > +early_param("amd_dynamic_epp", amd_dynamic_epp_param); > > MODULE_AUTHOR("Huang Rui "); > MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); > -- > 2.43.0 >