diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 881c0afabf17b5903624e49560466d68ffc8d071..ac1a24035fefe7d21a304cd79a5b07762acfc025 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -72,6 +72,7 @@
 #define DSI_VBP_NL		0x24
 #define DSI_VFP_NL		0x28
 #define DSI_VACT_NL		0x2C
+#define DSI_SIZE_CON		0x38
 #define DSI_HSA_WC		0x50
 #define DSI_HBP_WC		0x54
 #define DSI_HFP_WC		0x58
@@ -156,6 +157,7 @@ struct phy;
 struct mtk_dsi_driver_data {
 	const u32 reg_cmdq_off;
 	bool has_shadow_ctl;
+	bool has_size_ctl;
 };
 
 struct mtk_dsi {
@@ -424,6 +426,10 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
 	writel(vm->vfront_porch, dsi->regs + DSI_VFP_NL);
 	writel(vm->vactive, dsi->regs + DSI_VACT_NL);
 
+	if (dsi->driver_data->has_size_ctl)
+		writel(vm->vactive << 16 | vm->hactive,
+		       dsi->regs + DSI_SIZE_CON);
+
 	horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);
 
 	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)