diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
index 55fe398d8290..3040a79f298f 100644
--- a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
+++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
@@ -129,8 +129,7 @@ static int sun8i_tcon_top_bind(struct device *dev, struct device *master,
 	if (!tcon_top)
 		return -ENOMEM;
 
-	clk_data = devm_kzalloc(dev, sizeof(*clk_data) +
-				sizeof(*clk_data->hws) * CLK_NUM,
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, CLK_NUM),
 				GFP_KERNEL);
 	if (!clk_data)
 		return -ENOMEM;