[PATCH] skge: handle out of memory on ring changes

Please consider this for 2.6.15.1; it fixes several cases where
the skge driver can get in a bad state and later crash; if an
admin operation that causes a restart fails from out of memory.
Such as changing the MTU or increasing the ring size.

The fixes involve checking the return value and doing necessary
unwinds. Or in some cases avoiding doing a full restart.

The same code is the netdev-2.6 tree for 2.6.16 but as separate pieces
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/skge.c

@@ -43,7 +43,7 @@
 #include "skge.h"
 
 #define DRV_NAME		"skge"
-#define DRV_VERSION		"1.2"
+#define DRV_VERSION		"1.3"
 #define PFX			DRV_NAME " "
 
 #define DEFAULT_TX_RING_SIZE	128
@@ -88,15 +88,14 @@ MODULE_DEVICE_TABLE(pci, skge_id_table);
 
 static int skge_up(struct net_device *dev);
 static int skge_down(struct net_device *dev);
+static void skge_phy_reset(struct skge_port *skge);
 static void skge_tx_clean(struct skge_port *skge);
 static int xm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val);
 static int gm_phy_write(struct skge_hw *hw, int port, u16 reg, u16 val);
 static void genesis_get_stats(struct skge_port *skge, u64 *data);
 static void yukon_get_stats(struct skge_port *skge, u64 *data);
 static void yukon_init(struct skge_hw *hw, int port);
-static void yukon_reset(struct skge_hw *hw, int port);
 static void genesis_mac_init(struct skge_hw *hw, int port);
-static void genesis_reset(struct skge_hw *hw, int port);
 static void genesis_link_up(struct skge_port *skge);
 
 /* Avoid conditionals by using array */
@@ -276,10 +275,9 @@ static int skge_set_settings(struct net_device *dev, struct ethtool_cmd *ecmd)
 	skge->autoneg = ecmd->autoneg;
 	skge->advertising = ecmd->advertising;
 
-	if (netif_running(dev)) {
-		skge_down(dev);
-		skge_up(dev);
-	}
+	if (netif_running(dev))
+		skge_phy_reset(skge);
+
 	return (0);
 }
 
@@ -399,6 +397,7 @@ static int skge_set_ring_param(struct net_device *dev,
 			       struct ethtool_ringparam *p)
 {
 	struct skge_port *skge = netdev_priv(dev);
+	int err;
 
 	if (p->rx_pending == 0 || p->rx_pending > MAX_RX_RING_SIZE ||
 	    p->tx_pending == 0 || p->tx_pending > MAX_TX_RING_SIZE)
@@ -409,7 +408,11 @@ static int skge_set_ring_param(struct net_device *dev,
 
 	if (netif_running(dev)) {
 		skge_down(dev);
-		skge_up(dev);
+		err = skge_up(dev);
+		if (err)
+			dev_close(dev);
+		else
+			dev->set_multicast_list(dev);
 	}
 
 	return 0;
@@ -430,21 +433,11 @@ static void skge_set_msglevel(struct net_device *netdev, u32 value)
 static int skge_nway_reset(struct net_device *dev)
 {
 	struct skge_port *skge = netdev_priv(dev);
-	struct skge_hw *hw = skge->hw;
-	int port = skge->port;
 
 	if (skge->autoneg != AUTONEG_ENABLE || !netif_running(dev))
 		return -EINVAL;
 
-	spin_lock_bh(&hw->phy_lock);
-	if (hw->chip_id == CHIP_ID_GENESIS) {
-		genesis_reset(hw, port);
-		genesis_mac_init(hw, port);
-	} else {
-		yukon_reset(hw, port);
-		yukon_init(hw, port);
-	}
-	spin_unlock_bh(&hw->phy_lock);
+	skge_phy_reset(skge);
 	return 0;
 }
 
@@ -516,10 +509,8 @@ static int skge_set_pauseparam(struct net_device *dev,
 	else
 		skge->flow_control = FLOW_MODE_NONE;
 
-	if (netif_running(dev)) {
-		skge_down(dev);
-		skge_up(dev);
-	}
+	if (netif_running(dev))
+		skge_phy_reset(skge);
 	return 0;
 }
 
@@ -1935,7 +1926,6 @@ static void yukon_link_down(struct skge_port *skge)
 
 	}
 
-	yukon_reset(hw, port);
 	skge_link_down(skge);
 
 	yukon_init(hw, port);
@@ -2019,6 +2009,22 @@ static void yukon_phy_intr(struct skge_port *skge)
 	/* XXX restart autonegotiation? */
 }
 
+static void skge_phy_reset(struct skge_port *skge)
+{
+	struct skge_hw *hw = skge->hw;
+	int port = skge->port;
+
+	netif_stop_queue(skge->netdev);
+	netif_carrier_off(skge->netdev);
+
+	spin_lock_bh(&hw->phy_lock);
+	if (hw->chip_id == CHIP_ID_GENESIS)
+		genesis_mac_init(hw, port);
+	else
+		yukon_init(hw, port);
+	spin_unlock_bh(&hw->phy_lock);
+}
+
 /* Basic MII support */
 static int skge_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
@@ -2187,6 +2193,7 @@ static int skge_up(struct net_device *dev)
 	kfree(skge->rx_ring.start);
  free_pci_mem:
 	pci_free_consistent(hw->pdev, skge->mem_size, skge->mem, skge->dma);
+	skge->mem = NULL;
 
 	return err;
 }
@@ -2197,6 +2204,9 @@ static int skge_down(struct net_device *dev)
 	struct skge_hw *hw = skge->hw;
 	int port = skge->port;
 
+	if (skge->mem == NULL)
+		return 0;
+
 	if (netif_msg_ifdown(skge))
 		printk(KERN_INFO PFX "%s: disabling interface\n", dev->name);
 
@@ -2253,6 +2263,7 @@ static int skge_down(struct net_device *dev)
 	kfree(skge->rx_ring.start);
 	kfree(skge->tx_ring.start);
 	pci_free_consistent(hw->pdev, skge->mem_size, skge->mem, skge->dma);
+	skge->mem = NULL;
 	return 0;
 }
 
@@ -2413,18 +2424,23 @@ static void skge_tx_timeout(struct net_device *dev)
 
 static int skge_change_mtu(struct net_device *dev, int new_mtu)
 {
-	int err = 0;
-	int running = netif_running(dev);
+	int err;
 
 	if (new_mtu < ETH_ZLEN || new_mtu > ETH_JUMBO_MTU)
 		return -EINVAL;
 
+	if (!netif_running(dev)) {
+		dev->mtu = new_mtu;
+		return 0;
+	}
 
-	if (running)
 	skge_down(dev);
+
 	dev->mtu = new_mtu;
-	if (running)
-		skge_up(dev);
+
+	err = skge_up(dev);
+	if (err)
+		dev_close(dev);
 
 	return err;
 }
@@ -3398,8 +3414,8 @@ static int skge_resume(struct pci_dev *pdev)
 		struct net_device *dev = hw->dev[i];
 		if (dev) {
 			netif_device_attach(dev);
-			if (netif_running(dev))
-				skge_up(dev);
+			if (netif_running(dev) && skge_up(dev))
+				dev_close(dev);
 		}
 	}
 	return 0;