The only PHYs that are used with phylink which change their interface
are the BCM84881 and MV88X3310 family, both of which only change their
interface modes on link-up events.  However, rather than relying upon
this behaviour by the PHY, we should give a stronger guarantee when
resolving that the link will be down whenever we change the interface
mode.  This patch implements that stronger guarantee for resolve.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>