net/macb: check all address registers sets

The macb driver in u-boot uses the first register set while
the at91_ether driver in u-boot uses the second register set.

By checking all register set, like at91_ether does, this code
can be shared between the drivers.

This only changes behavior on macb if no vaild address
is found in the first register set.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.c

@@ -114,9 +114,12 @@ static void __init macb_get_hwaddr(struct macb *bp)
 	u32 bottom;
 	u16 top;
 	u8 addr[6];
+	int i;
 
-	bottom = macb_or_gem_readl(bp, SA1B);
-	top = macb_or_gem_readl(bp, SA1T);
+	/* Check all 4 address register for vaild address */
+	for (i = 0; i < 4; i++) {
+		bottom = macb_or_gem_readl(bp, SA1B + i * 8);
+		top = macb_or_gem_readl(bp, SA1T + i * 8);
 
 		addr[0] = bottom & 0xff;
 		addr[1] = (bottom >> 8) & 0xff;
@@ -127,10 +130,12 @@ static void __init macb_get_hwaddr(struct macb *bp)
 
 		if (is_valid_ether_addr(addr)) {
 			memcpy(bp->dev->dev_addr, addr, sizeof(addr));
-	} else {
+			return;
+		}
+	}
+
 	netdev_info(bp->dev, "invalid hw address, using random\n");
 	eth_hw_addr_random(bp->dev);
-	}
 }
 
 static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)