diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 5bed63eee5f0..050f9a59ed54 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1524,10 +1524,10 @@ static int vop_bind(struct device *dev, struct device *master, void *data)
 	vop_win_init(vop);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	vop->len = resource_size(res);
 	vop->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(vop->regs))
 		return PTR_ERR(vop->regs);
+	vop->len = resource_size(res);
 
 	vop->regsbak = devm_kzalloc(dev, vop->len, GFP_KERNEL);
 	if (!vop->regsbak)