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Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f0401064d7aa..0e69dffd5a76 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -3033,6 +3033,14 @@ static const struct x86_cpu_id hwp_support_ids[] __initconst = {
{}
};
+static bool intel_pstate_hwp_is_enabled(void)
+{
+ u64 value;
+
+ rdmsrl(MSR_PM_ENABLE, value);
+ return !!(value & 0x1);
+}
+
static int __init intel_pstate_init(void)
{
const struct x86_cpu_id *id;
@@ -3051,8 +3059,12 @@ static int __init intel_pstate_init(void)
* Avoid enabling HWP for processors without EPP support,
* because that means incomplete HWP implementation which is a
* corner case and supporting it is generally problematic.
+ *
+ * If HWP is enabled already, though, there is no choice but to
+ * deal with it.
*/
- if (!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) {
+ if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) ||
+ intel_pstate_hwp_is_enabled()) {
hwp_active++;
hwp_mode_bdw = id->driver_data;
intel_pstate.attr = hwp_cpufreq_attrs;