net: stmmac: check if MAC needs to attach to a PHY

After the introduction of the fixed-link support, the MAC driver
no longer attempt to scan for a PHY to attach to. This causes the
non fixed-link setups to stop working.

Using the phylink_expects_phy() to check and determine if the MAC
should expect and attach a PHY.

Fixes: ab21cf9 ("net: stmmac: make mdio register skips PHY scanning for fixed-link")
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Lai Peter Jun Ann <peter.jun.ann.lai@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: michaelsit-iotg

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1135,6 +1135,7 @@ static int stmmac_init_phy(struct net_device *dev)
 {
 	struct stmmac_priv *priv = netdev_priv(dev);
 	struct fwnode_handle *fwnode;
+	bool phy_needed;
 	int ret;
 
 	fwnode = of_fwnode_handle(priv->plat->phylink_node);
@@ -1144,10 +1145,11 @@ static int stmmac_init_phy(struct net_device *dev)
 	if (fwnode)
 		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
 
+	phy_needed = phylink_expects_phy(priv->phylink);
 	/* Some DT bindings do not set-up the PHY handle. Let's try to
 	 * manually parse it
 	 */
-	if (!fwnode || ret) {
+	if (!fwnode || phy_needed || ret) {
 		int addr = priv->plat->phy_addr;
 		struct phy_device *phydev;