[PATCH v2] arm64: dts: rockchip: Change ethernet TXD timing delay value

[Dongjin Kim]

On Tue, Aug 19, 2025 at 11:10:19PM +0800, Chukun Pan wrote:
> Hi,
> 
> > Very poor network performance is observed on the ODROID-M1 Board
> > (REV 1.0 20220613) when running iperf3 (under 200Mbits/sec), and
> > this problem can be resolved after changing the value of TXD
> > timing to 0x35 from 0x4f.
> 
> Can you try changing phy-mode to "rgmii-id" ?
> 
> ```
> --- a/arch/arm64/boot/dts/rockchip/rk3568-odroid-m1.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3568-odroid-m1.dts
> @@ -200,7 +200,7 @@ &gmac0 {
>  	assigned-clock-rates = <0>, <125000000>;
>  	clock_in_out = "output";
>  	phy-handle = <&rgmii_phy0>;
> -	phy-mode = "rgmii";
> +	phy-mode = "rgmii-id";
>  	phy-supply = <&vcc3v3_sys>;
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&gmac0_miim
> @@ -209,9 +209,6 @@ &gmac0_rx_bus2
>  		     &gmac0_rgmii_clk
>  		     &gmac0_rgmii_bus>;
>  	status = "okay";
> -
> -	tx_delay = <0x4f>;
> -	rx_delay = <0x2d>;
>  };
>  
>  &gpu {
> ```
> 
> --
> 2.25.1
> 
> 
Thank you for suggesting me to try 'rgmii-id' again.

I'd remember that 'rgmii-id' didn't work with the very early version of
the board, however your suggestion works. Let me test the change with
more boards and submit the new patch when it's done.

Thanks a lot.
Dongjin Kim.