When invalid keyword is specified, ifconfig(8) is silent about it, instead random request is sent to the driver.
Before the patch:
root@r-freeb43:~ # ifconfig mce0 mediaopt -txpause,-rxpause ifconfig: SIOCSIFMEDIA (media): Device not configured
After:
root@r-freeb43:~ # ifconfig mce0 mediaopt -txpause,-rxpause ifconfig: unknown option: -txpause
Sponsored by: Mellanox Technologies / NVidia Networking