xen-netfront: Update features after registering netdev

Update the features after calling register_netdev() otherwise the
device features are not set up correctly and it not possible to change
the MTU of the device. After this change, the features reported by
ethtool match the device's features before the commit which introduced
the issue and it is possible to change the device's MTU.

Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
Reported-by: Liam Shepherd <liam@dancer.es>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index ee4cb6cfde1ec875e3e1b395098929f058271f51..a57daecf1d574fc1a6e25ca5eb043c1617fe2dcc 100644 (file)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1951,10 +1951,6 @@ static int xennet_connect(struct net_device *dev)
        /* talk_to_netback() sets the correct number of queues */
        num_queues = dev->real_num_tx_queues;
 
-       rtnl_lock();
-       netdev_update_features(dev);
-       rtnl_unlock();
-
        if (dev->reg_state == NETREG_UNINITIALIZED) {
                err = register_netdev(dev);
                if (err) {
@@ -1964,6 +1960,10 @@ static int xennet_connect(struct net_device *dev)
                }
        }
 
+       rtnl_lock();
+       netdev_update_features(dev);
+       rtnl_unlock();
+
        /*
         * All public and private state should now be sane.  Get
         * ready to start sending and receiving packets and give the driver