[PATCH] 2.6.3 pcnet32.c bus master arbitration failure fix

Here is the first of several individual patches to 2.6.3 for the pcnet32
driver.

The driver did not properly serialize accesses to chip registers, resulting
in reading/writing the wrong register.  This patch eliminates this problem
and gets rid of the cause of the symptom of 'bus master arbitration failure'.

It was easier to use generic_mii_ioctl than modify the current pcnet32_ioctl
routine with the necessary locks.  This has been re-tested on an IA32 system.

drivers/net/pcnet32.c

@@ -720,6 +720,8 @@ pcnet32_probe1(unsigned long ioaddr, unsigned int irq_line, int shared,
     lp->name = chipname;
     lp->shared_irq = shared;
     lp->mii_if.full_duplex = fdx;
+    lp->mii_if.phy_id_mask = 0x1f;
+    lp->mii_if.reg_num_mask = 0x1f;
     lp->dxsuflo = dxsuflo;
     lp->ltint = ltint;
     lp->mii = mii;
@@ -1625,12 +1627,18 @@ static int pcnet32_ethtool_ioctl (struct net_device *dev, void *useraddr)
 	}
 	/* restart autonegotiation */
 	case ETHTOOL_NWAY_RST: {
-		return mii_nway_restart(&lp->mii_if);
+		int r;
+		spin_lock_irq(&lp->lock);
+		r = mii_nway_restart(&lp->mii_if);
+		spin_unlock_irq(&lp->lock);
+		return r;
 	}
 	/* get link status */
 	case ETHTOOL_GLINK: {
 		struct ethtool_value edata = {ETHTOOL_GLINK};
+		spin_lock_irq(&lp->lock);
 		edata.data = mii_link_ok(&lp->mii_if);
+		spin_unlock_irq(&lp->lock);
 		if (copy_to_user(useraddr, &edata, sizeof(edata)))
 			return -EFAULT;
 		return 0;
@@ -1661,45 +1669,37 @@ static int pcnet32_ethtool_ioctl (struct net_device *dev, void *useraddr)
 
 static int pcnet32_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 {
-    unsigned long ioaddr = dev->base_addr;
     struct pcnet32_private *lp = dev->priv;	 
     struct mii_ioctl_data *data = (struct mii_ioctl_data *)&rq->ifr_data;
-    int phyaddr = lp->a.read_bcr (ioaddr, 33);
+    int rc;
+    unsigned long flags;
 
     if (cmd == SIOCETHTOOL)
 	return pcnet32_ethtool_ioctl(dev, (void *) rq->ifr_data);
 
+    /* SIOC[GS]MIIxxx ioctls */
     if (lp->mii) {
-	switch(cmd) {
-	case SIOCGMIIPHY:		/* Get address of MII PHY in use. */
-	    data->phy_id = (phyaddr >> 5) & 0x1f;
-	    /* Fall Through */
-	case SIOCGMIIREG:		/* Read MII PHY register. */
-	    lp->a.write_bcr (ioaddr, 33, ((data->phy_id & 0x1f) << 5) | (data->reg_num & 0x1f));
-	    data->val_out = lp->a.read_bcr (ioaddr, 34);
-	    lp->a.write_bcr (ioaddr, 33, phyaddr);
-	    return 0;
-	case SIOCSMIIREG:		/* Write MII PHY register. */
-	    if (!capable(CAP_NET_ADMIN))
-		return -EPERM;
-	    lp->a.write_bcr (ioaddr, 33, ((data->phy_id & 0x1f) << 5) | (data->reg_num & 0x1f));
-	    lp->a.write_bcr (ioaddr, 34, data->val_in);
-	    lp->a.write_bcr (ioaddr, 33, phyaddr);
-	    return 0;
-	default:
-	    return -EOPNOTSUPP;
-	}
+	spin_lock_irqsave(&lp->lock, flags);
+	rc = generic_mii_ioctl(&lp->mii_if, data, cmd, NULL);
+	spin_unlock_irqrestore(&lp->lock, flags);
+    } else {
+	rc = -EOPNOTSUPP;
     }
-    return -EOPNOTSUPP;
+
+    return rc;
 }
 
 static void pcnet32_watchdog(struct net_device *dev)
 {
     struct pcnet32_private *lp = dev->priv;
+    unsigned long flags;
 
     /* Print the link status if it has changed */
-    if (lp->mii)
+    if (lp->mii) {
+	spin_lock_irqsave(&lp->lock, flags);
 	mii_check_media (&lp->mii_if, 1, 0);
+	spin_unlock_irqrestore(&lp->lock, flags);
+    }
 
     mod_timer (&(lp->watchdog_timer), PCNET32_WATCHDOG_TIMEOUT);
 }