yes, I have checked.
I have add some log in my baseline L4.1.15, found that phydev->phy_id is zero, does this means the phy chip is not work ?
fec 2188000.ethernet (unnamed net_device) (uninitialized): Invalid MAC address: 00:00:00:00:00:00
fec 2188000.ethernet (unnamed net_device) (uninitialized): Using random MAC address: 66:14:2a:50:c3:1a
Neil.zhang added here, before of_mdiobus_register
libphy: Neil.zhang added here, mido_register begin...
libphy: fec_enet_mii_bus: probed
libphy: Neil.zhang added here, phy_device_register
libphy: Neil.zhang added here, phy_scan_fixups
libphy: Neil.zhang added here, phy_uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_id is 0, uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_needs_fixup ret false, phy_uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_uid = 221561, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_id is 0, uid = 221561, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_needs_fixup ret false, phy_uid = 221561, uid_mask = ffffffff
Neil.zhang added here, phy_device_register ret zero
mdio_bus 2188000.ethernet: registered phy ethernet-phy at address 2
libphy: Neil.zhang added here, phy_device_register
libphy: Neil.zhang added here, phy_scan_fixups
libphy: Neil.zhang added here, phy_uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_id is 0, uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_needs_fixup ret false, phy_uid = 221560, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_uid = 221561, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_id is 0, uid = 221561, uid_mask = ffffffff
libphy: Neil.zhang added here, phy_needs_fixup ret false, phy_uid = 221561, uid_mask = ffffffff
Neil.zhang added here, phy_device_register ret zero
mdio_bus 2188000.ethernet: registered phy ethernet-phy at address 1
another question ? what about you mean that check IOMUXC_GPR, I have no idea about that.

for full dmesg log, please refer to attachment.
edit 2st:
