target/linux/mvebu/patches-5.15/700-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 @@ -4987,6 +4987,16 @@ static int mvneta_setup_tc(struct net_de
  13         }
  14  }
  15
  16 +#ifndef CONFIG_ARM64
  17 +static u16 mvneta_select_queue(struct net_device *dev, struct sk_buff *skb,
  18 +                              struct net_device *sb_dev)
  19 +{
  20 +       /* XXX: hardware queue scheduling is broken,
  21 +        * use only one queue until it is fixed */
  22 +       return 0;
  23 +}
  24 +#endif
  25 +
  26  static const struct net_device_ops mvneta_netdev_ops = {
  27         .ndo_open            = mvneta_open,
  28         .ndo_stop            = mvneta_stop,
  29 @@ -4997,6 +5007,9 @@ static const struct net_device_ops mvnet
  30         .ndo_fix_features    = mvneta_fix_features,
  31         .ndo_get_stats64     = mvneta_get_stats64,
  32         .ndo_eth_ioctl        = mvneta_ioctl,
  33 +#ifndef CONFIG_ARM64
  34 +       .ndo_select_queue    = mvneta_select_queue,
  35 +#endif
  36         .ndo_bpf             = mvneta_xdp,
  37         .ndo_xdp_xmit        = mvneta_xdp_xmit,
  38         .ndo_setup_tc        = mvneta_setup_tc,