Index: sys/arm64/arm64/intr_machdep.c
===================================================================
--- sys/arm64/arm64/intr_machdep.c
+++ sys/arm64/arm64/intr_machdep.c
@@ -431,11 +431,9 @@
 	struct arm64_intr_entry *intr;
 	int rv;
 
-	mtx_lock_spin(&intr_list_lock);
-	intr = intr_lookup_locked(hw_irq);
-	mtx_unlock_spin(&intr_list_lock);
+	intr = intr_allocate(hw_irq);
 	if (intr == NULL)
-		return (EINVAL);
+		return (ENOMEM);
 
 	intr->i_trig = trig;
 	intr->i_pol = pol;