Merge branch 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[karo-tx-linux.git] / drivers / net / tun.c

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 74e94054ab1a29d41828c7b9358518733eba0754..5235f48be1be677b7ca57fd275c21392fb846762 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -460,7 +460,23 @@ static u32 tun_net_fix_features(struct net_device *dev, u32 features)
 
        return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
 }
-
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void tun_poll_controller(struct net_device *dev)
+{
+       /*
+        * Tun only receives frames when:
+        * 1) the char device endpoint gets data from user space
+        * 2) the tun socket gets a sendmsg call from user space
+        * Since both of those are syncronous operations, we are guaranteed
+        * never to have pending data when we poll for it
+        * so theres nothing to do here but return.
+        * We need this though so netpoll recognizes us as an interface that
+        * supports polling, which enables bridge devices in virt setups to
+        * still use netconsole
+        */
+       return;
+}
+#endif
 static const struct net_device_ops tun_netdev_ops = {
        .ndo_uninit             = tun_net_uninit,
        .ndo_open               = tun_net_open,
@@ -468,6 +484,9 @@ static const struct net_device_ops tun_netdev_ops = {
        .ndo_start_xmit         = tun_net_xmit,
        .ndo_change_mtu         = tun_net_change_mtu,
        .ndo_fix_features       = tun_net_fix_features,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+       .ndo_poll_controller    = tun_poll_controller,
+#endif
 };
 
 static const struct net_device_ops tap_netdev_ops = {
@@ -480,6 +499,9 @@ static const struct net_device_ops tap_netdev_ops = {
        .ndo_set_multicast_list = tun_net_mclist,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_validate_addr      = eth_validate_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+       .ndo_poll_controller    = tun_poll_controller,
+#endif
 };
 
 /* Initialize net device. */