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>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e7e808d9..872c577 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1019,6 +1019,7 @@
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 @@
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 @@
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);
