Re: [PATCH v2 3/4] net: stmmac: Add glue layer for Loongson-1 SoC

[Andrew Lunn]

> > What about the other three RGMII modes? Plain rgmii is pretty unusual,
> > rgmii-id is the most used.
> >
> According to the LS1B datasheet, only RGMII and MII are supported.
> And I can confirm that MII mode does work for LS1B.

What does your device tree look like? What are you setting phy-mode to
in the rgmii case? As i said, "rgmii" is pretty unusual, you normally
need "rgmii-id".

Something in the system needs to add 2ns delays to the RGMII clock
lines. Generally in device tree you pass phy-mode = "rgmii-id"; The
MAC configures itself for RGMII, and passes
PHY_INTERFACE_MODE_RGMII_ID to the PHY when it is attached. The PHY
then inserts the delays.

What is inserting the delays in your system?

     Andrew