When I configure some of the T2080 SEDES into SGMII, in addition to the hardware configuration of the SERDES mode, in the T2080 SDK, there are some files need to modify the configuration, so that T2080 can identify the external SGMII PHY
Yes, it is needed to have correct PHY connection type specified in the DTS:
phy-connection-type = "sgmii";
You could refer to the Linux sources repository:
sdk/linux.git - Freescale PowerPC Linux Tree
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