When the interface is up, using ethtool breaks it because:
a) link is put down but media_timer interval is not shortened to NO_LINK
b) rxtx is stopped but not restarted
Also manual 10baseT-HD (and probably FD too - untested) mode does not work -
the link is forced up, packets are transmitted but nothing is received.
Changing CSR14 value to match documentation (not disabling link check) fixes this.
Signed-off-by: Ondrej Zary<linux@xxxxxxxxxxxxxxxxxxxx>