--- a/sys/dev/drm/radeon/si_dpm.c
+++ b/sys/dev/drm/radeon/si_dpm.c
@@ -4043,7 +4043,7 @@
 {
 	unsigned int i;
 
-	for (i = 0; i < voltage_table->count; i++)
+	for (i = 0; i < voltage_table->count && i < SISLANDS_MAX_NO_VREG_STEPS; i++)
 		table->lowSMIO[i] |= cpu_to_be32(voltage_table->entries[i].smio_low);
 }