I got a Micrel instead of Marvell or TI and get the same warning. You can easily search it in the codes. In my case, the auto negotiation fails at the PHY and a link is not set up. With SDK, in the "Board Support Package Settings" for lwIP, it is possible to change auto negotiation to fixed speed. I did that and fixed the speed also on the other side of the link. Then a link is set up and the example echo server worked, though with some kind of delays. Ping timeout sometimes.
You could also do a search for Micrel and lwIP and find a lot of clues to your question.