r8152: Refresh MAC address during USBDEVFS_RESET

On some platforms it is possible to dynamically change the policy
of what MAC address is selected from the ASL at runtime.

These tools will reset the USB device and expect the change to be
made immediately.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/r8152.c

@@ -1220,39 +1220,51 @@ static int vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr *sa)
 	return ret;
 }
 
-static int set_ethernet_addr(struct r8152 *tp)
+static int determine_ethernet_addr(struct r8152 *tp, struct sockaddr *sa)
 {
 	struct net_device *dev = tp->netdev;
-	struct sockaddr sa;
 	int ret;
 
 	if (tp->version == RTL_VER_01) {
-		ret = pla_ocp_read(tp, PLA_IDR, 8, sa.sa_data);
+		ret = pla_ocp_read(tp, PLA_IDR, 8, sa->sa_data);
 	} else {
 		/* if device doesn't support MAC pass through this will
 		 * be expected to be non-zero
 		 */
-		ret = vendor_mac_passthru_addr_read(tp, &sa);
+		ret = vendor_mac_passthru_addr_read(tp, sa);
 		if (ret < 0)
-			ret = pla_ocp_read(tp, PLA_BACKUP, 8, sa.sa_data);
+			ret = pla_ocp_read(tp, PLA_BACKUP, 8, sa->sa_data);
 	}
 
 	if (ret < 0) {
 		netif_err(tp, probe, dev, "Get ether addr fail\n");
-	} else if (!is_valid_ether_addr(sa.sa_data)) {
+	} else if (!is_valid_ether_addr(sa->sa_data)) {
 		netif_err(tp, probe, dev, "Invalid ether addr %pM\n",
-			  sa.sa_data);
+			  sa->sa_data);
 		eth_hw_addr_random(dev);
-		ether_addr_copy(sa.sa_data, dev->dev_addr);
-		ret = rtl8152_set_mac_address(dev, &sa);
+		ether_addr_copy(sa->sa_data, dev->dev_addr);
 		netif_info(tp, probe, dev, "Random ether addr %pM\n",
-			   sa.sa_data);
-	} else {
+			   sa->sa_data);
+		return 0;
+	}
+
+	return ret;
+}
+
+static int set_ethernet_addr(struct r8152 *tp)
+{
+	struct net_device *dev = tp->netdev;
+	struct sockaddr sa;
+	int ret;
+
+	ret = determine_ethernet_addr(tp, &sa);
+	if (ret < 0)
+		return ret;
+
 	if (tp->version == RTL_VER_01)
 		ether_addr_copy(dev->dev_addr, sa.sa_data);
 	else
 		ret = rtl8152_set_mac_address(dev, &sa);
-	}
 
 	return ret;
 }
@@ -4263,10 +4275,18 @@ static int rtl8152_post_reset(struct usb_interface *intf)
 {
 	struct r8152 *tp = usb_get_intfdata(intf);
 	struct net_device *netdev;
+	struct sockaddr sa;
 
 	if (!tp)
 		return 0;
 
+	/* reset the MAC adddress in case of policy change */
+	if (determine_ethernet_addr(tp, &sa) >= 0) {
+		rtnl_lock();
+		dev_set_mac_address (tp->netdev, &sa, NULL);
+		rtnl_unlock();
+	}
+
 	netdev = tp->netdev;
 	if (!netif_running(netdev))
 		return 0;