On Thu, 17 Sep 2020, Michael van Elst wrote:
The RK3328 only has a single controller (GMAC), but it does have two interfaces for PHYs, one MII (10/100Mbps) where the PHY is internal, and one RGMII (10/100/1000Mbps) for an external PHY. The main board has such an external PHY that is used for Gigabit Ethernet.
RK3328 has two GMAC controllers.