Question on verifying ethernet driver

Hi

I have written ethernet driver and successfully verfied most of the
entry points. Open, close, send, receive, ioctl functions & interrupt
handler have been thoroughly verified. I have released the driver
internally for developers in my company. They seems to have no problem.
However, now I realized that there are couple of function still not
touched or covered. One of them I have no clue to verify. That is,
tx_timeout function. Could anyone point me or provide me some details
on how to verify this tx_timeout function. I felt, while transferring a
file I can disconnect the cable but that does not seems to invoke this
function. One more I am thinking is reducing the time_out value to
virtually to zero.

Any suggestions and comments are welcome.

thanks,
adar