[NET] front: Zero negotiated bits in xen_set_features

When we reconnect to the backend we need to first zero all negotiated
bits as the functions xen_set_sg and xen_set_tso do not (and are not
supposed to) zero bits when they fail to set them.

This patch also permanently enables the NETIF_F_GSO_ROBUST bit as we
never parse any GSO fields ourselves (even if we did the backend could
not trust us so it's wasted effort).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 36c0ef266c40792162e0721b264a06daf8fb9a25..016f4d1220be75ad0a2a416b8e61e284e5870dde 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -1112,6 +1112,11 @@ static int xennet_set_tso(struct net_device *dev, u32 data)
 
 static void xennet_set_features(struct net_device *dev)
 {
+       /* Turn off all GSO bits except ROBUST. */
+       dev->features &= (1 << NETIF_F_GSO_SHIFT) - 1;
+       dev->features |= NETIF_F_GSO_ROBUST;
+       xennet_set_sg(dev, 0);
+
        if (!xennet_set_sg(dev, 1))
                xennet_set_tso(dev, 1);
 }