path: root/net/8021q/vlan_dev.c
diff options
authorVlad Yasevich <vyasevich@gmail.com>2017-05-05 16:17:41 -0400
committerDavid S. Miller <davem@davemloft.net>2017-05-08 14:39:19 -0400
commit8403debeead8e8b296d7a7db2174af524695ab42 (patch)
treee99d202db8c54a3f32d2b49c174aa5b1cf776210 /net/8021q/vlan_dev.c
parenttcp: make congestion control optionally skip slow start after idle (diff)
vlan: Keep NETIF_F_HW_CSUM similar to other software devices
Vlan devices, like all other software devices, enable NETIF_F_HW_CSUM feature. However, unlike all the othe other software devices, vlans will switch to using IP|IPV6_CSUM features, if the underlying devices uses them. In these situations, checksum offload features on the vlan device can't be controlled via ethtool. This patch makes vlans keep HW_CSUM feature if the underlying device supports checksum offloading. This makes vlan devices behave like other software devices, and restores control to the user. A side-effect is that some offload settings (typically UFO) may be enabled on the vlan device while being disabled on the HW. However, the GSO code will correctly process the packets. This actually results in slightly better raw throughput. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/8021q/vlan_dev.c')
1 files changed, 10 insertions, 3 deletions
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 9ee5787634e5..953b6728bd00 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -626,11 +626,18 @@ static netdev_features_t vlan_dev_fix_features(struct net_device *dev,
struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
netdev_features_t old_features = features;
+ netdev_features_t lower_features;
- features = netdev_intersect_features(features, real_dev->vlan_features);
- features |= NETIF_F_RXCSUM;
- features = netdev_intersect_features(features, real_dev->features);
+ lower_features = netdev_intersect_features((real_dev->vlan_features |
+ real_dev->features);
+ /* Add HW_CSUM setting to preserve user ability to control
+ * checksum offload on the vlan device.
+ */
+ if (lower_features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
+ lower_features |= NETIF_F_HW_CSUM;
+ features = netdev_intersect_features(features, lower_features);
features |= old_features & (NETIF_F_SOFT_FEATURES | NETIF_F_GSO_SOFTWARE);
features |= NETIF_F_LLTX;