net: phy: phylink: fix SFP interface autodetection

When connecting SFP PHY to phylink use the detected interface.
Otherwise, the link fails to come up when the configured 'phy-mode'
differs from the SFP detected mode.

Move most of phylink_connect_phy() into __phylink_connect_phy(), and
leave phylink_connect_phy() as a wrapper. phylink_sfp_connect_phy() can
now pass the SFP detected PHY interface to __phylink_connect_phy().

This fixes 1GB SFP module link up on eth3 of the Macchiatobin board that
is configured in the DT to "2500base-x" phy-mode.

Fixes: 9525ae83959b6 ("phylink: add phylink infrastructure")
Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phylink.c

@@ -717,6 +717,30 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
 	return 0;
 }
 
+static int __phylink_connect_phy(struct phylink *pl, struct phy_device *phy,
+		phy_interface_t interface)
+{
+	int ret;
+
+	if (WARN_ON(pl->link_an_mode == MLO_AN_FIXED ||
+		    (pl->link_an_mode == MLO_AN_INBAND &&
+		     phy_interface_mode_is_8023z(interface))))
+		return -EINVAL;
+
+	if (pl->phydev)
+		return -EBUSY;
+
+	ret = phy_attach_direct(pl->netdev, phy, 0, interface);
+	if (ret)
+		return ret;
+
+	ret = phylink_bringup_phy(pl, phy);
+	if (ret)
+		phy_detach(phy);
+
+	return ret;
+}
+
 /**
  * phylink_connect_phy() - connect a PHY to the phylink instance
  * @pl: a pointer to a &struct phylink returned from phylink_create()
@@ -734,31 +758,13 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy)
  */
 int phylink_connect_phy(struct phylink *pl, struct phy_device *phy)
 {
-	int ret;
-
-	if (WARN_ON(pl->link_an_mode == MLO_AN_FIXED ||
-		    (pl->link_an_mode == MLO_AN_INBAND &&
-		     phy_interface_mode_is_8023z(pl->link_interface))))
-		return -EINVAL;
-
-	if (pl->phydev)
-		return -EBUSY;
-
 	/* Use PHY device/driver interface */
 	if (pl->link_interface == PHY_INTERFACE_MODE_NA) {
 		pl->link_interface = phy->interface;
 		pl->link_config.interface = pl->link_interface;
 	}
 
-	ret = phy_attach_direct(pl->netdev, phy, 0, pl->link_interface);
-	if (ret)
-		return ret;
-
-	ret = phylink_bringup_phy(pl, phy);
-	if (ret)
-		phy_detach(phy);
-
-	return ret;
+	return __phylink_connect_phy(pl, phy, pl->link_interface);
 }
 EXPORT_SYMBOL_GPL(phylink_connect_phy);
 
@@ -1672,7 +1678,9 @@ static void phylink_sfp_link_up(void *upstream)
 
 static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
 {
-	return phylink_connect_phy(upstream, phy);
+	struct phylink *pl = upstream;
+
+	return __phylink_connect_phy(upstream, phy, pl->link_config.interface);
 }
 
 static void phylink_sfp_disconnect_phy(void *upstream)