Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index dc32f34..80c1a83 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -254,12 +254,25 @@
  */
 int cpuidle_register_driver(struct cpuidle_driver *drv)
 {
+	struct cpuidle_governor *gov;
 	int ret;
 
 	spin_lock(&cpuidle_driver_lock);
 	ret = __cpuidle_register_driver(drv);
 	spin_unlock(&cpuidle_driver_lock);
 
+	if (!ret && !strlen(param_governor) && drv->governor &&
+	    (cpuidle_get_driver() == drv)) {
+		mutex_lock(&cpuidle_lock);
+		gov = cpuidle_find_governor(drv->governor);
+		if (gov) {
+			cpuidle_prev_governor = cpuidle_curr_governor;
+			if (cpuidle_switch_governor(gov) < 0)
+				cpuidle_prev_governor = NULL;
+		}
+		mutex_unlock(&cpuidle_lock);
+	}
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cpuidle_register_driver);
@@ -274,9 +287,21 @@
  */
 void cpuidle_unregister_driver(struct cpuidle_driver *drv)
 {
+	bool enabled = (cpuidle_get_driver() == drv);
+
 	spin_lock(&cpuidle_driver_lock);
 	__cpuidle_unregister_driver(drv);
 	spin_unlock(&cpuidle_driver_lock);
+
+	if (!enabled)
+		return;
+
+	mutex_lock(&cpuidle_lock);
+	if (cpuidle_prev_governor) {
+		if (!cpuidle_switch_governor(cpuidle_prev_governor))
+			cpuidle_prev_governor = NULL;
+	}
+	mutex_unlock(&cpuidle_lock);
 }
 EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);