phylink: restart 802.3z negotiation when starting net device

Restart 802.3z negotiation when the net device is brought up to ensure
that the link partner has our current link modes.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/phylink.c

@@ -751,6 +751,12 @@ void phylink_start(struct phylink *pl)
 	phylink_resolve_flow(pl, &pl->link_config);
 	phylink_mac_config(pl, &pl->link_config);
 
+	/* Restart autonegotiation if using 802.3z to ensure that the link
+	 * parameters are properly negotiated.  This is necessary for DSA
+	 * switches using 802.3z negotiation to ensure they see our modes.
+	 */
+	phylink_mac_an_restart(pl);
+
 	clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
 	phylink_run_resolve(pl);