netvsc: fix net poll mode

The ndo_poll_controller function needs to schedule NAPI to pick
up arriving packets and send completions. Otherwise no data
will ever be received. For simple case of netconsole, it also
will allow send completions to happen.  Without this netpoll
will eventually get stuck.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/netvsc_drv.c

@@ -1158,11 +1158,22 @@ netvsc_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
-static void netvsc_poll_controller(struct net_device *net)
+static void netvsc_poll_controller(struct net_device *dev)
 {
-	/* As netvsc_start_xmit() works synchronous we don't have to
-	 * trigger anything here.
-	 */
+	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *ndev;
+	int i;
+
+	rcu_read_lock();
+	ndev = rcu_dereference(ndc->nvdev);
+	if (ndev) {
+		for (i = 0; i < ndev->num_chn; i++) {
+			struct netvsc_channel *nvchan = &ndev->chan_table[i];
+
+			napi_schedule(&nvchan->napi);
+		}
+	}
+	rcu_read_unlock();
 }
 #endif