diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 167058470675..7c125decacc0 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1598,7 +1598,7 @@ static void vop_crtc_enable(struct drm_crtc *crtc)
 		VOP_CTRL_SET(vop, vs_st_end_f1, val);
 		VOP_CTRL_SET(vop, dsp_interlace, 1);
 		VOP_CTRL_SET(vop, p2i_en, 1);
-		vtotal = vtotal + 1;
+		vtotal += vtotal + 1;
 	} else {
 		VOP_CTRL_SET(vop, dsp_interlace, 0);
 		VOP_CTRL_SET(vop, p2i_en, 0);