ibmveth: Fix max MTU limit

The max MTU limit defined for ibmveth is not accounting for
virtual ethernet buffer overhead, which is twenty-two additional
bytes set aside for the ethernet header and eight additional bytes
of an opaque handle reserved for use by the hypervisor. Update the
max MTU to reflect this overhead.

Fixes: d894be57ca92 ("ethernet: use net core MTU range checking in more drivers")
Fixes: 110447f8269a ("ethernet: fix min/max MTU typos")
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 96d36ae5049e13ae09b2af251b73d2806da798fa..c5c732601e35ec909ff1c5f13871198bacc8e1e0 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1715,7 +1715,7 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
        }
 
        netdev->min_mtu = IBMVETH_MIN_MTU;
-       netdev->max_mtu = ETH_MAX_MTU;
+       netdev->max_mtu = ETH_MAX_MTU - IBMVETH_BUFF_OH;
 
        memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);