A submitted qmap/rmnet packet size can not be larger than the linked interface (real_dev) MTU. This patch ensures that the rmnet virtual iface MTU is configured according real device capability.
Signed-off-by: Loic Poulain <loic.poul...@linaro.org> --- drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c index d58b51d..d1d7328 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c @@ -60,9 +60,14 @@ static netdev_tx_t rmnet_vnd_start_xmit(struct sk_buff *skb, static int rmnet_vnd_change_mtu(struct net_device *rmnet_dev, int new_mtu) { + struct rmnet_priv *priv = netdev_priv(rmnet_dev); + if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE) return -EINVAL; + if (priv->real_dev && (new_mtu + RMNET_NEEDED_HEADROOM) > priv->real_dev->mtu) + return -EINVAL; + rmnet_dev->mtu = new_mtu; return 0; } @@ -242,6 +247,9 @@ int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev, priv->real_dev = real_dev; + /* Align default MTU with real_dev MTU */ + rmnet_vnd_change_mtu(rmnet_dev, real_dev->mtu - RMNET_NEEDED_HEADROOM); + rc = register_netdevice(rmnet_dev); if (!rc) { ep->egress_dev = rmnet_dev; -- 2.7.4