MII can't read phy registers

Hello,The MII phy register can’t be read, in one of my firmware versions. All that appear in MII Read Register (0xff80054c) is 0x0000ffff. As a result, the routines mii_identify_phy and mii_reset don’t work. I try read the documentation to find out anothers bits or registers related with this register, and can’t find a clear relation. Anyone has some clues or tips? Thanks, Cassius Resende Duarte

in my case, there was two problems to get phy_id from PHY. first one was the device id of PHY was wrong. check this point. and second one was the PHY had broken.