On Tue, Aug 22, 2023 at 11:20 PM Andrew Lunn <andrew@xxxxxxx> wrote: > > > > 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? > I understand the delay issue of RGMII. Just tried phy-mode = "rgmii-id", it still works. I will use PHY_INTERFACE_MODE_RGMII_ID instead. Thanks! > Andrew > -- Best regards, Keguang Zhang