Icenowy, On 10/26/20 7:12 AM, Andrew Lunn wrote: >> By referring to linux/phy.h, NA means not applicable. This surely >> do not apply when RGMII is really in use. > > It means the PHY driver should not touch the mode, something else has > set it up. That could be strapping, the bootloader, ACPI firmware, > whatever. > >> I think no document declares RGMII must have all internal delays >> of the PHY explicitly disabled. It just says RGMII. > > Please take a look at all the other PHY drivers. They should all > disable delays when passed PHY_INTERFACE_MODE_RGMII. Documentation/networking/phy.rst also makes this clear: PHY_INTERFACE_MODE_RGMII: the PHY is not responsible for inserting any internal delay by itself, it assumes that either the Ethernet MAC (if capable or the PCB traces) insert the correct 1.5-2ns delay Regards, Samuel