Does change in PHY require device tree update

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
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1

We have custom board for AGX Xavier Industrial which uses PHY VSC8531 (uses MDIO) instead of 88E1512PB2
If i try to change the mdio → phy@0 in device tree to VSC8531, the ethernet gets detected during bootloader but stops working during kernel is getting loaded and giving the following error and ethernet disappears

Could not attach to PHY
Cannot attach to PHY (error: -19)

If i leave the dts unchanged, then ethernet is working in linux as well but we doubt whether 1Gbps is working.

Do we need to do any change in device tree ?

3

If default one can work, then it should be fine.

Actually I don’t understand what change you did here.

If i try to change the mdio → phy@0 in device tree to VSC8531

4

But we are afraid the default eqos driver might not support all the VSC8531 features

Below is the DTS change

Existing DTS:

ethernet@2490000 {
    compatible = "nvidia,nveqos";
    reg = <0x00 0x2490000 0x00 0x10000>;
    reg-names = "mac-base";

–

    mdio {
        compatible = "nvidia,eqos-mdio";
        #address-cells = <0x01>;
        #size-cells = <0x00>;

        phy@0 {
            reg = <0x00>;
            interrupt-parent = <0x0b>;
            interrupts = <0x34 0x08>;
            marvell,copper-mode;
            marvell,reg-init = <0x03 0x12 0x7fff 0x880>;
            phandle = <0x21>;
        };
    };

–
};

Changed DTS:

ethernet@2490000 {
    compatible = "nvidia,nveqos";
    reg = <0x00 0x2490000 0x00 0x10000>;
    reg-names = "mac-base";

–

    mdio {
        ethernet-phy@0 {
            compatible = "ethernet-phy-id0007.0570";
            vsc8531,vddmac = <1800>;
            vsc8531,edge-slowdown = <0x00>;
            vsc8531,led-0-mode = <0x01>;
            vsc8531,led-1-mode = <0x02>;
            phandle = <0x21>;
        };
    };

–

};
5

It could be vsc PHY driver was not present in the k5.10 driver base.

Please take a look first.

6

The VSC8531 was not enabled by default in the tegra linux defconfig
We enabled it and trying it.

By using the default eqos driver, the VSC8531 PHY seems to work.
But we are unsure whether this supports all the features of VSC8531 and risk of any issue in any untested scenario.

And why enabling of the actual vsc8531 driver makes the PHY not working, suspecting some configuration issue.

If we are able to make the VSC8531 PHY work with its correct driver, then we can be sure that the PHY chip is supported well.

8

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