skge: handle irq better on single port card

Most boards with SysKonnect/Marvell Ethernet have only a single port.
For the single port case, use the standard Ethernet driver convention
of allocating IRQ when device is brought up rather than at probe time.

This patch also adds some additional read after writes to avoid any
PCI posting problems when setting the IRQ mask.

The error handling of dual port cards is also changed.  If second port
can not be brought up, then just fail. No point in continuing, since
the failure is most certainly because of out of memory.

It is worth noting that the dual port skge device has a single irq but two
seperate status rings and therefore has two NAPI objects, one for
each port.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/skge.c

@@ -113,6 +113,7 @@ static void yukon_init(struct skge_hw *hw, int port);
 static void genesis_mac_init(struct skge_hw *hw, int port);
 static void genesis_link_up(struct skge_port *skge);
 static void skge_set_multicast(struct net_device *dev);
+static irqreturn_t skge_intr(int irq, void *dev_id);
 
 /* Avoid conditionals by using array */
 static const int txqaddr[] = { Q_XA1, Q_XA2 };
@@ -2568,6 +2569,16 @@ static int skge_up(struct net_device *dev)
 	if (err)
 		goto free_rx_ring;
 
+	if (hw->ports == 1) {
+		err = request_irq(hw->pdev->irq, skge_intr, IRQF_SHARED,
+				  dev->name, hw);
+		if (err) {
+			netdev_err(dev, "Unable to allocate interrupt %d error: %d\n",
+				   hw->pdev->irq, err);
+			goto free_tx_ring;
+		}
+	}
+
 	/* Initialize MAC */
 	spin_lock_bh(&hw->phy_lock);
 	if (is_genesis(hw))
@@ -2595,11 +2606,14 @@ static int skge_up(struct net_device *dev)
 	spin_lock_irq(&hw->hw_lock);
 	hw->intr_mask |= portmask[port];
 	skge_write32(hw, B0_IMSK, hw->intr_mask);
+	skge_read32(hw, B0_IMSK);
 	spin_unlock_irq(&hw->hw_lock);
 
 	napi_enable(&skge->napi);
 	return 0;
 
+ free_tx_ring:
+	kfree(skge->tx_ring.start);
  free_rx_ring:
 	skge_rx_clean(skge);
 	kfree(skge->rx_ring.start);
@@ -2640,9 +2654,13 @@ static int skge_down(struct net_device *dev)
 
 	spin_lock_irq(&hw->hw_lock);
 	hw->intr_mask &= ~portmask[port];
-	skge_write32(hw, B0_IMSK, hw->intr_mask);
+	skge_write32(hw, B0_IMSK, (hw->ports == 1) ? 0 : hw->intr_mask);
+	skge_read32(hw, B0_IMSK);
 	spin_unlock_irq(&hw->hw_lock);
 
+	if (hw->ports == 1)
+		free_irq(hw->pdev->irq, hw);
+
 	skge_write8(skge->hw, SK_REG(skge->port, LNK_LED_REG), LED_OFF);
 	if (is_genesis(hw))
 		genesis_stop(skge);
@@ -3603,7 +3621,8 @@ static int skge_reset(struct skge_hw *hw)
 	skge_write32(hw, B2_IRQM_INI, skge_usecs2clk(hw, 100));
 	skge_write32(hw, B2_IRQM_CTRL, TIM_START);
 
-	skge_write32(hw, B0_IMSK, hw->intr_mask);
+	/* Leave irq disabled until first port is brought up. */
+	skge_write32(hw, B0_IMSK, 0);
 
 	for (i = 0; i < hw->ports; i++) {
 		if (is_genesis(hw))
@@ -3930,31 +3949,39 @@ static int __devinit skge_probe(struct pci_dev *pdev,
 		goto err_out_free_netdev;
 	}
 
-	err = request_irq(pdev->irq, skge_intr, IRQF_SHARED, hw->irq_name, hw);
-	if (err) {
-		dev_err(&pdev->dev, "%s: cannot assign irq %d\n",
-		       dev->name, pdev->irq);
-		goto err_out_unregister;
-	}
 	skge_show_addr(dev);
 
 	if (hw->ports > 1) {
 		dev1 = skge_devinit(hw, 1, using_dac);
-		if (dev1 && register_netdev(dev1) == 0)
-			skge_show_addr(dev1);
-		else {
-			/* Failure to register second port need not be fatal */
-			dev_warn(&pdev->dev, "register of second port failed\n");
-			hw->dev[1] = NULL;
-			hw->ports = 1;
-			if (dev1)
-				free_netdev(dev1);
+		if (!dev1) {
+			err = -ENOMEM;
+			goto err_out_unregister;
 		}
+
+		err = register_netdev(dev1);
+		if (err) {
+			dev_err(&pdev->dev, "cannot register second net device\n");
+			goto err_out_free_dev1;
+		}
+
+		err = request_irq(pdev->irq, skge_intr, IRQF_SHARED,
+				  hw->irq_name, hw);
+		if (err) {
+			dev_err(&pdev->dev, "cannot assign irq %d\n",
+				pdev->irq);
+			goto err_out_unregister_dev1;
+		}
+
+		skge_show_addr(dev1);
 	}
 	pci_set_drvdata(pdev, hw);
 
 	return 0;
 
+err_out_unregister_dev1:
+	unregister_netdev(dev1);
+err_out_free_dev1:
+	free_netdev(dev1);
 err_out_unregister:
 	unregister_netdev(dev);
 err_out_free_netdev:
@@ -3992,14 +4019,19 @@ static void __devexit skge_remove(struct pci_dev *pdev)
 
 	spin_lock_irq(&hw->hw_lock);
 	hw->intr_mask = 0;
-	skge_write32(hw, B0_IMSK, 0);
-	skge_read32(hw, B0_IMSK);
+
+	if (hw->ports > 1) {
+		skge_write32(hw, B0_IMSK, 0);
+		skge_read32(hw, B0_IMSK);
+		free_irq(pdev->irq, hw);
+	}
 	spin_unlock_irq(&hw->hw_lock);
 
 	skge_write16(hw, B0_LED, LED_STAT_OFF);
 	skge_write8(hw, B0_CTST, CS_RST_SET);
 
-	free_irq(pdev->irq, hw);
+	if (hw->ports > 1)
+		free_irq(pdev->irq, hw);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 	if (dev1)