[PATCH] cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP

[PATCH] cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP

[Mario Limonciello]

There are some performance issues being identified by dynamic EPP
and we don't want to have distributions turning it on by default
exposing them to users at this time.

Drop the kconfig option, and require an explicit opt in from kernel
command line or runtime sysfs option to turn it on.

Reported-by: Viktor Jägersküpper" <viktor_jaegerskuepper@freenet.de>
Closes: https://lore.kernel.org/linux-pm/14a87c99-785c-4b16-bfce-35ecbf053448@freenet.de/
Reported-by: Stuart Meckle <stuartmeckle@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 Documentation/admin-guide/pm/amd-pstate.rst |  9 ++++-----
 drivers/cpufreq/Kconfig.x86                 | 12 ------------
 drivers/cpufreq/amd-pstate.c                |  4 ----
 3 files changed, 4 insertions(+), 21 deletions(-)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index f8e7050fc7623..b53c752d58ca0 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -358,8 +358,8 @@ Dynamic energy performance profile
 The amd-pstate driver supports dynamically selecting the energy performance
 profile based on whether the machine is running on AC or DC power.
 
-Whether this behavior is enabled by default depends on the kernel
-config option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`. This behavior can also be overridden
+Whether this behavior is enabled by default depends on the kernel command line option
+``amd_dynamic_epp`` is set. This behavior can also be overridden
 at runtime by the sysfs file ``/sys/devices/system/cpu/cpufreq/policyX/dynamic_epp``.
 
 When set to enabled, the driver will select a different energy performance
@@ -485,9 +485,8 @@ 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``.
+autonomously changes the EPP mode. The default is disabled. It can be enabled
+with the kernel parameter ``amd_dynamic_epp=enable``.
 
 User Space Interface in ``sysfs`` - General
 ===========================================
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index 027e6ea2e0384..a9093cd5e5d1b 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -70,18 +70,6 @@ config X86_AMD_PSTATE_DEFAULT_MODE
 	  For details, take a look at:
 	  <file:Documentation/admin-guide/pm/amd-pstate.rst>.
 
-config X86_AMD_PSTATE_DYNAMIC_EPP
-	bool "AMD Processor P-State dynamic EPP support"
-	depends on X86_AMD_PSTATE
-	default n
-	help
-	  Allow the kernel to dynamically change the energy performance
-	  value from events like ACPI platform profile and AC adapter plug
-	  events.
-
-	  This feature can also be changed at runtime, this configuration
-	  option only sets the kernel default value behavior.
-
 config X86_AMD_PSTATE_UT
 	tristate "selftest for AMD Processor P-State driver"
 	depends on X86 && ACPI_PROCESSOR
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 2234044c328ba..3f06e33f47120 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -87,11 +87,7 @@ static struct cpufreq_driver amd_pstate_driver;
 static struct cpufreq_driver amd_pstate_epp_driver;
 static int cppc_state = AMD_PSTATE_UNDEFINED;
 static bool amd_pstate_prefcore = true;
-#ifdef CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP
-static bool dynamic_epp = CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP;
-#else
 static bool dynamic_epp;
-#endif
 static struct quirk_entry *quirks;
 
 /*
-- 
2.43.0

Re: [PATCH] cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP

[K Prateek Nayak]

Hello Mario,

On 5/13/2026 3:49 AM, Mario Limonciello wrote:
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -358,8 +358,8 @@ Dynamic energy performance profile
>  The amd-pstate driver supports dynamically selecting the energy performance
>  profile based on whether the machine is running on AC or DC power.
>  
> -Whether this behavior is enabled by default depends on the kernel
> -config option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`. This behavior can also be overridden
> +Whether this behavior is enabled by default depends on the kernel command line option
> +``amd_dynamic_epp`` is set. This behavior can also be overridden
>  at runtime by the sysfs file ``/sys/devices/system/cpu/cpufreq/policyX/dynamic_epp``.

Unrelated nit.

This file should have been
/sys/devices/system/cpu/amd_pstate/dynamic_epp right?

Apart from that, feel free to add:

Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>

>  
>  When set to enabled, the driver will select a different energy performance
-- 
Thanks and Regards,
Prateek

Re: [PATCH] cpufreq/amd-pstate: Drop Kconfig option for dynamic EPP

[Mario Limonciello]

On 5/14/26 08:05, K Prateek Nayak wrote:
> Hello Mario,
> 
> On 5/13/2026 3:49 AM, Mario Limonciello wrote:
>> --- a/Documentation/admin-guide/pm/amd-pstate.rst
>> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
>> @@ -358,8 +358,8 @@ Dynamic energy performance profile
>>   The amd-pstate driver supports dynamically selecting the energy performance
>>   profile based on whether the machine is running on AC or DC power.
>>   
>> -Whether this behavior is enabled by default depends on the kernel
>> -config option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`. This behavior can also be overridden
>> +Whether this behavior is enabled by default depends on the kernel command line option
>> +``amd_dynamic_epp`` is set. This behavior can also be overridden
>>   at runtime by the sysfs file ``/sys/devices/system/cpu/cpufreq/policyX/dynamic_epp``.
> 
> Unrelated nit.
> 
> This file should have been
> /sys/devices/system/cpu/amd_pstate/dynamic_epp right?
> 

Correct; thanks.  I'll roll that in.

> Apart from that, feel free to add:
> 
> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>

Appreciated.

> 
>>   
>>   When set to enabled, the driver will select a different energy performance