PATCH: 3c59x 00:00:00:00:00:00 MAC failure

[Alan Cox <alan@redhat.com>]

The 3com EEPROM has a checksum but unfortunately it seems that a zapped
EEPROM returning all zero values passes the checksum test fine and we try
and use it. 


--- drivers/net/3c59x.c~	2004-09-29 17:23:42.964453264 +0100
+++ drivers/net/3c59x.c	2004-09-29 17:28:40.358242536 +0100
@@ -1295,6 +1295,13 @@
 		for (i = 0; i < 6; i++)
 			printk("%c%2.2x", i ? ':' : ' ', dev->dev_addr[i]);
 	}
+	/* Unfortunately an all zero eeprom passes the checksum and this
+	   gets found in the wild in failure cases. Crypto is hard 8) */
+	if (memcmp(dev->dev_addr, "\0\0\0\0\0", 6) == 0) {
+		retval = -EINVAL;
+		printk(KERN_ERR "*** EEPROM MAC address is invalid.\n");
+		goto free_ring;	/* With every pack */
+	}
 	EL3WINDOW(2);
 	for (i = 0; i < 6; i++)
 		outb(dev->dev_addr[i], ioaddr + i);