diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 9b2a2961fca85efb29161dad7c84c17dc742feb0..2e74b02ed96bed17b7275e46cdf887010b050963 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -608,7 +608,7 @@ static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
 					  u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
-	u8 dpcd_ext[6];
+	u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
 	int ret;
 
 	/*