[BPI-R3(mt7986a)] + 2.5G yt8821 phy, when link up 2.5G, ping OK, link up others speed(10/100/1000M), ping fail

[otto]

Hi

Issue description:

Based on BPI-R3 evb,

When yt8821 2.5G phy serdes is configed to “force 2500Base-x“ mode,

Only link up speed 2.5G ping ok, other link up speed(10/10/1000M) ping fail

Detail below:

1. Device config in

BPI-Router-Linux-6.10-rc/arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts

gmac0: mac@0 {

	compatible = "mediatek,eth-mac";

	reg = <0>;

	phy-mode = "2500base-x";


	fixed-link {

		speed = <2500>;

		full-duplex;

		pause;

	};

};

gmac1: mac@1 {

	compatible = "mediatek,eth-mac";

	reg = <1>;

	**phy-mode = "2500base-x";**

	//phy-mode = "sgmii";

	**phy-handle = <&phy7>;**

	//sfp = <&sfp1>;

	//managed = "in-band-status";

};

mdio: mdio-bus {
	#address-cells = <1>;
	#size-cells = <0>;
};

};

&mdio {

switch: switch@31 {

	compatible = "mediatek,mt7531";

	reg = <31>;

	interrupt-controller;

	#interrupt-cells = <1>;

	interrupts-extended = <&pio 66 IRQ_TYPE_LEVEL_HIGH>;

	reset-gpios = <&pio 5 GPIO_ACTIVE_HIGH>;

};

phy7: ethernet-phy@7 {

	compatible = "ethernet-phy-id4f51.ea19";

	**phy-mode = "2500base-x";**

	//phy-mode = "sgmii";

	reg = <0x7>;

	full-duplex;

	pause;

};

};

2. topology like bpi-r3-mini(2.5G phy is en881h)

Mt7986a gmac1<2.5G serdes>yt8821 phy

3. test env snapshot below
   

Could anyone give me some advice and how to debug the issue?

Appreciate your help!

[ericwoud (Eric W.)]

The devicetree is similar to the R3mini with the en8811h, so that’s all ok.

If you have the phy operating at fixed 2500base-x, you will need to:

static int yt8821_get_rate_matching(struct phy_device *phydev, phy_interface_t iface)
{
    return RATE_MATCH_PAUSE;
}

Add the function pointer in the driver table of the phy.

AND set:

phydev->rate_matching = RATE_MATCH_PAUSE;

Somewhere in probe() / config_init() or read_status() of your phy driver.

OR

If you want serdes switching between 2500base-x and sgmii, then have a look at the rtl8221b code of the 6.10+ kernel, we added that there.

https://patchwork.kernel.org/project/netdevbpf/list/?series=842685&state=%2A&archive=both

See commits 1/6 and 2/6

[Dale (Elad)]

Don’t place the PCB on that antistatic bag, it might create a short circuit

[moore (moore liu)]

I’m just curious, why don’t you use an SFP-to-SMA or SFP-to-SFP connection for the YT8821 board?