diff --git a/drivers/bus/mhi/core/mhi_init.c b/drivers/bus/mhi/core/mhi_init.c
index 526d7fd140e8..f026131cf3ab 100644
--- a/drivers/bus/mhi/core/mhi_init.c
+++ b/drivers/bus/mhi/core/mhi_init.c
@@ -92,9 +92,12 @@ struct mhi_controller *find_mhi_controller_by_name(const char *name)
 
 const char *to_mhi_pm_state_str(enum MHI_PM_STATE state)
 {
-	int index = find_last_bit((unsigned long *)&state, 32);
+	int index;
 
-	if (index >= ARRAY_SIZE(mhi_pm_state_str))
+	if (state)
+		index = __fls(state);
+
+	if (!state || index >= ARRAY_SIZE(mhi_pm_state_str))
 		return "Invalid State";
 
 	return mhi_pm_state_str[index];