Commit 6be26498 authored by Dirk Brandewie's avatar Dirk Brandewie Committed by Rafael J. Wysocki
Browse files

cpufreq / intel_pstate: Add kernel command line option disable intel_pstate. 



When intel_pstate is configured into the kernel it will become the
preferred scaling driver for processors that it supports.  Allow the
user to override this by adding:
   intel_pstate=disable
on the kernel command line.

Signed-off-by: default avatarDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent da0d9fda

Documentation/kernel-parameters.txt

+5 −0
Original line number Diff line number Diff line
@@ -1131,6 +1131,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			0	disables intel_idle and fall back on acpi_idle.

			1 to 6	specify maximum depth of C-state.



	intel_pstate=  [X86]

		       disable

		         Do not enable intel_pstate as the default

		         scaling driver for the supported processors



	intremap=	[X86-64, Intel-IOMMU]

			on	enable Interrupt Remapping (default)

			off	disable Interrupt Remapping

drivers/cpufreq/intel_pstate.c

+16 −0
Original line number Diff line number Diff line
@@ -773,11 +773,16 @@ static void intel_pstate_exit(void) 
}

module_exit(intel_pstate_exit);



static int __initdata no_load;



static int __init intel_pstate_init(void)

{

	int rc = 0;

	const struct x86_cpu_id *id;



	if (no_load)

		return -ENODEV;



	id = x86_match_cpu(intel_pstate_cpu_ids);

	if (!id)

		return -ENODEV;
@@ -802,6 +807,17 @@ out: 
}

device_initcall(intel_pstate_init);



static int __init intel_pstate_setup(char *str)

{

	if (!str)

		return -EINVAL;



	if (!strcmp(str, "disable"))

		no_load = 1;

	return 0;

}

early_param("intel_pstate", intel_pstate_setup);



MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");

MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");

MODULE_LICENSE("GPL");

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