--- zzzz-none-000/linux-2.6.39.4/net/bridge/br_device.c	2011-08-03 19:43:28.000000000 +0000
+++ puma6-atom-6490-729/linux-2.6.39.4/net/bridge/br_device.c	2021-11-10 13:38:18.000000000 +0000
@@ -152,18 +152,24 @@
 }
 
 /* Allow setting mac address to any valid ethernet address. */
-static int br_set_mac_address(struct net_device *dev, void *p)
+static int br_set_mac_address(struct net_device *dev, void *addr_struct_p)
 {
-	struct net_bridge *br = netdev_priv(dev);
-	struct sockaddr *addr = p;
-
-	if (!is_valid_ether_addr(addr->sa_data))
-		return -EINVAL;
+	struct net_bridge *br;
+	struct sockaddr *addr = (struct sockaddr *)(addr_struct_p);
+	unsigned char br_mac_zero[6] = {0,0,0,0,0,0};
 
+	br = netdev_priv(dev);
 	spin_lock_bh(&br->lock);
-	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
-	br_stp_change_bridge_id(br, addr->sa_data);
-	br->flags |= BR_SET_MAC_ADDR;
+
+	if (!memcmp(addr->sa_data, br_mac_zero, ETH_ALEN)) {
+		if (br->automatic_mac_disabled) {
+			br->automatic_mac_disabled = 0;
+			br_stp_recalculate_bridge_id(br);
+		}
+	} else {
+		br->automatic_mac_disabled = 1;
+		br_stp_set_bridge_id(br, addr->sa_data);
+	}
 	spin_unlock_bh(&br->lock);
 
 	return 0;