KSZ9893 is a 3 port ethernet switch; port 1 and 2 incorporate 10/100/1000 Mbps PHYs. Port 3 has interfaces that can be configured as RGMII, MII or RMII. Port 3 is connected directly to iMX8mq.
Because Port 3 does not have PHY, so I think cannot treat it as an ethernet tranciver (eg. AR8031 in imx8mq-evk). I do some modify in kernel device tree but it still not working; cannot obtain IP address too.
There is 125 MHz on both TX Clock and RX Clock; Already measured by oscilloscope. It still cannot obtain IP address.
If anyone who has experience on ethernet switch, please help. My kernel version is 4.9.123.