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path: root/drivers/cpufreq/intel_pstate.c
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Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 8e23a698ce04..7e0f7880b21a 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2464,7 +2464,7 @@ static struct cpufreq_driver intel_cpufreq = {
.name = "intel_cpufreq",
};
-static struct cpufreq_driver *default_driver = &intel_pstate;
+static struct cpufreq_driver *default_driver;
static void intel_pstate_driver_cleanup(void)
{
@@ -2677,6 +2677,8 @@ static struct acpi_platform_list plat_info[] __initdata = {
{ } /* End */
};
+#define BITMASK_OOB (BIT(8) | BIT(18))
+
static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
{
const struct x86_cpu_id *id;
@@ -2686,8 +2688,9 @@ static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
id = x86_match_cpu(intel_pstate_cpu_oob_ids);
if (id) {
rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
- if (misc_pwr & (1 << 8)) {
- pr_debug("Bit 8 in the MISC_PWR_MGMT MSR set\n");
+ if (misc_pwr & BITMASK_OOB) {
+ pr_debug("Bit 8 or 18 in the MISC_PWR_MGMT MSR set\n");
+ pr_debug("P states are controlled in Out of Band mode by the firmware/hardware\n");
return true;
}
}
@@ -2755,6 +2758,7 @@ static int __init intel_pstate_init(void)
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;
+ default_driver = &intel_pstate;
goto hwp_cpu_matched;
}
} else {
@@ -2772,7 +2776,8 @@ static int __init intel_pstate_init(void)
return -ENODEV;
}
/* Without HWP start in the passive mode. */
- default_driver = &intel_cpufreq;
+ if (!default_driver)
+ default_driver = &intel_cpufreq;
hwp_cpu_matched:
/*
@@ -2817,6 +2822,8 @@ static int __init intel_pstate_setup(char *str)
if (!strcmp(str, "disable")) {
no_load = 1;
+ } else if (!strcmp(str, "active")) {
+ default_driver = &intel_pstate;
} else if (!strcmp(str, "passive")) {
default_driver = &intel_cpufreq;
no_hwp = 1;