Re: [PATCH 2/2] arm64: dts: rockchip: Add EmbedFire LubanCat 4 board

[Andrew Lunn]

> +&gmac1 {
> +	clock_in_out = "output";
> +	phy-handle = <&rgmii_phy1>;
> +	/* The board has 1.5ns delays on RX lines; TX delay is provided by the MAC. */

That is pretty unusual. How is this RX delay done?

> +	phy-mode = "rgmii-rxid";
> +	pinctrl-0 = <&gmac1_miim
> +		     &gmac1_tx_bus2
> +		     &gmac1_rx_bus2
> +		     &gmac1_rgmii_clk
> +		     &gmac1_rgmii_bus>;
> +	pinctrl-names = "default";
> +	tx_delay = <0x1b>;

please take a read of:

https://elixir.bootlin.com/linux/v6.15/source/Documentation/devicetree/bindings/net/ethernet-controller.yaml#L287

Ideally, you want to the PHY adding the delay, not the MAC. 99% of
rockchip boards get this wrong, they have phy-mode 'rgmii', and
{tx|rx}_delay properties. And i tell developers to swap to 'rgmii-id'
and remove the delay properties.

With the PCB adding some delays, you board is slightly
different. Please drop the tx_delay and adjust the phy-mode so the PHY
adds the delay.

	Andrew