On Thu, Jan 22, 2026 at 09:41:19AM +0800, Chaoyi Chen wrote:

Hi Andrew,

On 1/21/2026 9:15 PM, Andrew Lunn wrote:

quoted

quoted

+&mdio0 {
+	rgmii_phy0: ethernet-phy@1 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <0x1>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&rgmii_phy0_rst>;
+		reset-assert-us = <20000>;
+		reset-deassert-us = <100000>;
+		reset-gpios = <&gpio3 RK_PD3 GPIO_ACTIVE_LOW>;
+		tx-internal-delay-ps = <1900>;

What PHY is this? Does it actually implement this property?

It is also close to the 2000ps default. Have you put the board in an
environment chamber and run tests at -20C to +70C to see if it will
work with the default 2000ps?

It is MotorComm yt8xxx PHY. I chose 1950 here because I find that
the MotorComm PHY binding only offer the options of 1950 or 2100. 

Without the property it should default to something near to 2000. Most
MAC/PHY pairs should work without this property, if the board is
designed correctly. So i suggest you only have a tx-internal-delay-ps
if it is required.

   Andrew