net: stmmac: update MAC capabilities when tx queues are updated

Upon boot up, the driver will configure the MAC capabilities based on
the maximum number of tx and rx queues. When the user changes the
tx queues to single queue, the MAC should be capable of supporting Half
Duplex, but the driver does not update the MAC capabilities when it is
configured so.

Using the stmmac_reinit_queues() to check the number of tx queues
and set the MAC capabilities accordingly.

Fixes: 0366f7e0 ("net: stmmac: add ethtool support for get/set channels")
Cc: <stable@vger.kernel.org> # 5.17+
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Gan, Yi Fang <yi.fang.gan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -1197,6 +1197,17 @@ static int stmmac_init_phy(struct net_device *dev)
 	return ret;
 }
 
+static void stmmac_set_half_duplex(struct stmmac_priv *priv)
+{
+	/* Half-Duplex can only work with single tx queue */
+	if (priv->plat->tx_queues_to_use > 1)
+		priv->phylink_config.mac_capabilities &=
+			~(MAC_10HD | MAC_100HD | MAC_1000HD);
+	else
+		priv->phylink_config.mac_capabilities |=
+			(MAC_10HD | MAC_100HD | MAC_1000HD);
+}
+
 static int stmmac_phy_setup(struct stmmac_priv *priv)
 {
 	struct stmmac_mdio_bus_data *mdio_bus_data;
@@ -1228,10 +1239,7 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
 						MAC_10FD | MAC_100FD |
 						MAC_1000FD;
 
-	/* Half-Duplex can only work with single queue */
-	if (priv->plat->tx_queues_to_use <= 1)
-		priv->phylink_config.mac_capabilities |= MAC_10HD | MAC_100HD |
-							 MAC_1000HD;
+	stmmac_set_half_duplex(priv);
 
 	/* Get the MAC specific capabilities */
 	stmmac_mac_phylink_get_caps(priv);
@@ -7172,6 +7180,7 @@ int stmmac_reinit_queues(struct net_device *dev, u32 rx_cnt, u32 tx_cnt)
 			priv->rss.table[i] = ethtool_rxfh_indir_default(i,
 									rx_cnt);
 
+	stmmac_set_half_duplex(priv);
 	stmmac_napi_add(dev);
 
 	if (netif_running(dev))