From: Mario Limonciello <mario.limonciello@amd.com>
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 <mario.limonciello@amd.com>
---
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 fb8752b42ec85..1afe6d8ab09bb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -392,6 +392,13 @@
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: <a>,<b>
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 2e076650dc77c..8424e7119dd7e 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -438,6 +438,13 @@ 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_pstate_epp=enable`` or disabled with ``amd_pstate_epp=disable``.
+
User Space Interface in ``sysfs`` - General
===========================================
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 7f203495f60e3..8172bd4b5952f 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1934,8 +1934,19 @@ 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 <ray.huang@amd.com>");
MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");
--
2.43.0
On 3/21/2025 7:58 AM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> Add `amd_dynamic_epp=enable` and `amd_dynamic_epp=disable` to override
> the kernel configuration option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`
> locally.
>
Small correction below, apart from that LGTM
Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> 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 fb8752b42ec85..1afe6d8ab09bb 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -392,6 +392,13 @@
> 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: <a>,<b>
> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
> index 2e076650dc77c..8424e7119dd7e 100644
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -438,6 +438,13 @@ 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_pstate_epp=enable`` or disabled with ``amd_pstate_epp=disable``.
/s/amd_pstate_epp/amd_dynamic_epp/
> +
> User Space Interface in ``sysfs`` - General
> ===========================================
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 7f203495f60e3..8172bd4b5952f 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1934,8 +1934,19 @@ 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 <ray.huang@amd.com>");
> MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");
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