about Network in Uclinux

I have already built a dm9000a module in uclinux

here's the abstract of startup information:

<DM9KS> I/O: 806810f8, VID: 90000a46

However , when running ping operation in uclinux system.

It appears the following information:

/> ping baidu.com

NETDEV WATCHDOG: eth0: transmit timed out

TX time-out -- dmfe_timeout().

The eth0 network interface is occuring in the system.

Help me!~~~~