ethtool: enable GSO and GRO by default

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 17 insertions, 4 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d08ef653857..168e3ad14da 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -984,6 +984,9 @@ struct net_device {
                                  NETIF_F_SG | NETIF_F_HIGHDMA |         \
                                  NETIF_F_FRAGLIST)
 
+        /* changeable features with no special hardware requirements */
+#define NETIF_F_SOFT_FEATURES   (NETIF_F_GSO | NETIF_F_GRO)
+
         /* Interface index. Unique device identifier    */
         int                     ifindex;
         int                     iflink;
diff --git a/net/core/dev.c b/net/core/dev.c
index 4580460ebec..8686f6ffe7f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5274,6 +5274,12 @@ u32 netdev_fix_features(struct net_device *dev, u32 features)
                 features &= ~NETIF_F_TSO;
         }
 
+        /* Software GSO depends on SG. */
+        if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
+                netdev_info(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
+                features &= ~NETIF_F_GSO;
+        }
+
         /* UFO needs SG and checksumming */
         if (features & NETIF_F_UFO) {
                 /* maybe split UFO into V4 and V6? */
@@ -5430,11 +5436,15 @@ int register_netdevice(struct net_device *dev)
         if (dev->iflink == -1)
                 dev->iflink = dev->ifindex;
 
-        dev->features = netdev_fix_features(dev, dev->features);
+        /* Enable software offloads by default - will be stripped in
+         * netdev_fix_features() if not supported. */
+        dev->features |= NETIF_F_SOFT_FEATURES;
 
-        /* Enable software GSO if SG is supported. */
-        if (dev->features & NETIF_F_SG)
-                dev->features |= NETIF_F_GSO;
+        /* Avoid warning from netdev_fix_features() for GSO without SG */
+        if (!(dev->features & NETIF_F_SG))
+                dev->features &= ~NETIF_F_GSO;
+
+        dev->features = netdev_fix_features(dev, dev->features);
 
         /* Enable GRO and NETIF_F_HIGHDMA for vlans by default,
          * vlan_dev_init() will do the dev->features check, so these features