ftgmac100: Cleanup speed/duplex tracking and fix duplex config

Keep track of both the current speed and duplex settings
instead of only speed and properly apply the duplex setting
to the HW.

This reworks the adjust_link() function to also avoid trying
to reconfigure the HW when there is no link and to display
the link state to the user.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/faraday/ftgmac100.c

@@ -79,7 +79,8 @@ struct ftgmac100 {
 	struct mii_bus *mii_bus;
 
 	/* Link management */
-	int old_speed;
+	int cur_speed;
+	int cur_duplex;
 	bool use_ncsi;
 
 	/* Misc */
@@ -212,16 +213,15 @@ static void ftgmac100_init_hw(struct ftgmac100 *priv)
 				 FTGMAC100_MACCR_RXDMA_EN	| \
 				 FTGMAC100_MACCR_TXMAC_EN	| \
 				 FTGMAC100_MACCR_RXMAC_EN	| \
-				 FTGMAC100_MACCR_FULLDUP	| \
 				 FTGMAC100_MACCR_CRC_APD	| \
 				 FTGMAC100_MACCR_RX_RUNT	| \
 				 FTGMAC100_MACCR_RX_BROADPKT)
 
-static void ftgmac100_start_hw(struct ftgmac100 *priv, int speed)
+static void ftgmac100_start_hw(struct ftgmac100 *priv)
 {
 	int maccr = MACCR_ENABLE_ALL;
 
-	switch (speed) {
+	switch (priv->cur_speed) {
 	default:
 	case 10:
 		break;
@@ -235,6 +235,9 @@ static void ftgmac100_start_hw(struct ftgmac100 *priv, int speed)
 		break;
 	}
 
+	if (priv->cur_duplex == DUPLEX_FULL)
+		maccr |= FTGMAC100_MACCR_FULLDUP;
+
 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
 }
 
@@ -854,12 +857,31 @@ static void ftgmac100_adjust_link(struct net_device *netdev)
 {
 	struct ftgmac100 *priv = netdev_priv(netdev);
 	struct phy_device *phydev = netdev->phydev;
+	int new_speed;
 	int ier;
 
-	if (phydev->speed == priv->old_speed)
+	/* We store "no link" as speed 0 */
+	if (!phydev->link)
+		new_speed = 0;
+	else
+		new_speed = phydev->speed;
+
+	if (phydev->speed == priv->cur_speed &&
+	    phydev->duplex == priv->cur_duplex)
 		return;
 
-	priv->old_speed = phydev->speed;
+	/* Print status if we have a link or we had one and just lost it,
+	 * don't print otherwise.
+	 */
+	if (new_speed || priv->cur_speed)
+		phy_print_status(phydev);
+
+	priv->cur_speed = new_speed;
+	priv->cur_duplex = phydev->duplex;
+
+	/* Link is down, do nothing else */
+	if (!new_speed)
+		return;
 
 	ier = ioread32(priv->base + FTGMAC100_OFFSET_IER);
 
@@ -871,7 +893,7 @@ static void ftgmac100_adjust_link(struct net_device *netdev)
 
 	netif_start_queue(netdev);
 	ftgmac100_init_hw(priv);
-	ftgmac100_start_hw(priv, phydev->speed);
+	ftgmac100_start_hw(priv);
 
 	/* re-enable interrupts */
 	iowrite32(ier, priv->base + FTGMAC100_OFFSET_IER);
@@ -1091,6 +1113,20 @@ static int ftgmac100_open(struct net_device *netdev)
 		goto err_irq;
 	}
 
+	/* When using NC-SI we force the speed to 100Mbit/s full duplex,
+	 *
+	 * Otherwise we leave it set to 0 (no link), the link
+	 * message from the PHY layer will handle setting it up to
+	 * something else if needed.
+	 */
+	if (priv->use_ncsi) {
+		priv->cur_duplex = DUPLEX_FULL;
+		priv->cur_speed = SPEED_100;
+	} else {
+		priv->cur_duplex = 0;
+		priv->cur_speed = 0;
+	}
+
 	priv->rx_pointer = 0;
 	priv->tx_clean_pointer = 0;
 	priv->tx_pointer = 0;
@@ -1101,7 +1137,7 @@ static int ftgmac100_open(struct net_device *netdev)
 		goto err_hw;
 
 	ftgmac100_init_hw(priv);
-	ftgmac100_start_hw(priv, priv->use_ncsi ? 100 : 10);
+	ftgmac100_start_hw(priv);
 
 	/* Clear stale interrupts */
 	status = ioread32(priv->base + FTGMAC100_OFFSET_ISR);