intel_powerclamp: Fix cstate counter detection.

Having all zero cstate count doesn't necesserily mean the cstate
counter is no functional.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c
index 8f181b3f842b3b04b12d972da58d8f238b6a7a00..67b608ef2cb276b6a9f4bfa0d339e289e50a0fea 100644 (file)
--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -206,6 +206,15 @@ static void find_target_mwait(void)
 
 }
 
+static bool has_pkg_state_counter(void)
+{
+       u64 tmp;
+       return !rdmsrl_safe(MSR_PKG_C2_RESIDENCY, &tmp) ||
+              !rdmsrl_safe(MSR_PKG_C3_RESIDENCY, &tmp) ||
+              !rdmsrl_safe(MSR_PKG_C6_RESIDENCY, &tmp) ||
+              !rdmsrl_safe(MSR_PKG_C7_RESIDENCY, &tmp);
+}
+
 static u64 pkg_state_counter(void)
 {
        u64 val;
@@ -500,7 +509,7 @@ static int start_power_clamp(void)
        struct task_struct *thread;
 
        /* check if pkg cstate counter is completely 0, abort in this case */
-       if (!pkg_state_counter()) {
+       if (!has_pkg_state_counter()) {
                pr_err("pkg cstate counter not functional, abort\n");
                return -EINVAL;
        }