How to mask the Ethernet SMA config port in device tree

On my carrier board, a switch chip was used,the RGMII port of the Xavier is connected to this switch chip.The SMA port(MDIO MDC)of this switch chip is connected to a MCU which is not Xavier.Currently,the MCU can communicate on Ethernet through the switch chip,that means the switch chip is working OK.But Now the Ethernet of the Xavier is not working.when powered up,i used command dmesg to check the error info,i found that the reason is the that driver can not detect PHY,the info show below.How can i mask it?

nvidia@jetson-0423418009920:~$ dmesg |grep -i eth
[    0.000000] psci: probing for conduit method from DT.
[    0.936566] iommu: Adding device 2490000.ether_qos to group 4
[    4.326727] igb: Intel(R) Gigabit Ethernet Network Driver - version 5.4.0-k
[    4.328860] eqos 2490000.ether_qos: no PHY interrupt found
[    4.333043] eqos 2490000.ether_qos: No prod values found
[    4.333709] eqos 2490000.ether_qos: Setting local MAC: 0 4 4b cb a3 e6
[   15.911846] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   15.911994] eth0: Could not attach to PHY
[   15.913414] net eth0: eqos_open: Cannot attach to PHY (error: -19)
[   80.034470] eqos 2490000.ether_qos eth0: PHY is not registered
[  137.121654] eqos 2490000.ether_qos eth0: PHY is not registered

i figured it out.change it to fixed phy link.

Could you tell me how to do it ?
I had the same problem.
How exactly do you operate it ?