target/linux/mvebu/patches-4.4/400-mvneta-tx-queue-workaround.patch

   1 The hardware queue scheduling is apparently configured with fixed
   2 priorities, which creates a nasty fairness issue where traffic from one
   3 CPU can starve traffic from all other CPUs.
   4
   5 Work around this issue by forcing all tx packets to go through one CPU,
   6 until this issue is fixed properly.
   7
   8 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   9 ---
  10 --- a/drivers/net/ethernet/marvell/mvneta.c
  11 +++ b/drivers/net/ethernet/marvell/mvneta.c
  12 @@ -3984,6 +3984,16 @@ static int mvneta_ethtool_set_eee(struct
  13         return phylink_ethtool_set_eee(pp->phylink, eee);
  14  }
  15
  16 +static u16 mvneta_select_queue(struct net_device *dev, struct sk_buff *skb,
  17 +                              void *accel_priv,
  18 +                              select_queue_fallback_t fallback)
  19 +{
  20 +       /* XXX: hardware queue scheduling is broken,
  21 +        * use only one queue until it is fixed */
  22 +       return 0;
  23 +}
  24 +
  25 +
  26  static const struct net_device_ops mvneta_netdev_ops = {
  27         .ndo_open            = mvneta_open,
  28         .ndo_stop            = mvneta_stop,
  29 @@ -3994,6 +4004,7 @@ static const struct net_device_ops mvnet
  30         .ndo_fix_features    = mvneta_fix_features,
  31         .ndo_get_stats64     = mvneta_get_stats64,
  32         .ndo_do_ioctl        = mvneta_ioctl,
  33 +       .ndo_select_queue    = mvneta_select_queue,
  34  };
  35
  36  const struct ethtool_ops mvneta_eth_tool_ops = {