diff --git a/arch/arm/dts/rk3399-u-boot.dtsi b/arch/arm/dts/rk3399-u-boot.dtsi
index 9815dc5..b39fe39 100644
--- a/arch/arm/dts/rk3399-u-boot.dtsi
+++ b/arch/arm/dts/rk3399-u-boot.dtsi
@@ -136,6 +136,12 @@
 
 &uart2 {
 	bootph-all;
+	clock-frequency = <24000000>;
+};
+
+&uart2c_xfer {
+	bootph-pre-sram;
+	bootph-pre-ram;
 };
 
 &vopb {