Re: [PATCH 4/4] arm64: dts: imx8ulp-evk: enable fec

+&fec {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_enet>;
+	phy-mode = "rmii";

Is this really a Fast Ethernet? Not 1G?

+	phy-handle = <&ethphy>;
+	status = "okay";
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ethphy: ethernet-phy {
+			reg = <1>;

I'm surprised this does not give warnings from the DTS tools. There is
a reg value, so it should be ethernet-phy@1

  Andrew