diff options
| author | Kristen Carlson Accardi <kristen@linux.intel.com> | 2015-02-06 13:41:55 -0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-02-06 22:54:18 +0100 |
| commit | d64c3b0bb9195d4de856d841337368d930cdb0ed (patch) | |
| tree | 489d9b39dde1926a2769c47ce185ef3a48d524c9 | |
| parent | 17ad13ba842bd5c197e20c17e107788aa0498ba9 (diff) | |
intel_pstate: provide option to only use intel_pstate with HWP
Allow users the option to disable the driver for any hardware
which does not support HWP.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 6 |
2 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4df73da11adc..07e6701a1439 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1469,6 +1469,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. no_hwp Do not enable hardware P state control (HWP) if available. + hwp_only + Only load intel_pstate on systems which support + hardware P state control (HWP) if available. intremap= [X86-64, Intel-IOMMU] on enable Interrupt Remapping (default) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index e7e808d9a8af..872c5772c5d3 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1019,6 +1019,7 @@ static struct cpufreq_driver intel_pstate_driver = { static int __initdata no_load; static int __initdata no_hwp; +static int __initdata hwp_only; static unsigned int force_load; static int intel_pstate_msrs_not_valid(void) @@ -1216,6 +1217,9 @@ static int __init intel_pstate_init(void) if (cpu_has(c,X86_FEATURE_HWP) && !no_hwp) intel_pstate_hwp_enable(); + if (!hwp_active && hwp_only) + goto out; + rc = cpufreq_register_driver(&intel_pstate_driver); if (rc) goto out; @@ -1250,6 +1254,8 @@ static int __init intel_pstate_setup(char *str) no_hwp = 1; if (!strcmp(str, "force")) force_load = 1; + if (!strcmp(str, "hwp_only")) + hwp_only = 1; return 0; } early_param("intel_pstate", intel_pstate_setup); |