Commit da8afb1c authored by Mario Limonciello (AMD)'s avatar Mario Limonciello (AMD)
Browse files

cpufreq/amd-pstate: add kernel command line to override dynamic epp 



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: default avatarMario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: default avatarGautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: default avatarMario Limonciello (AMD) <superm1@kernel.org>
parent e30ca6dd

Documentation/admin-guide/kernel-parameters.txt

+7 −0
Original line number Diff line number Diff line
@@ -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: <a>,<b>

Documentation/admin-guide/pm/amd-pstate.rst

+7 −0
Original line number Diff line number Diff line
@@ -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

===========================================

drivers/cpufreq/amd-pstate.c

+11 −0
Original line number Diff line number Diff line
@@ -2227,8 +2227,19 @@ 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");