target/linux/mvebu/patches-6.1/700-mvneta-tx-queue-workaround.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: mvneta: tx queue workaround
   3
   4 The hardware queue scheduling is apparently configured with fixed
   5 priorities, which creates a nasty fairness issue where traffic from one
   6 CPU can starve traffic from all other CPUs.
   7
   8 Work around this issue by forcing all tx packets to go through one CPU,
   9 until this issue is fixed properly.
  10
  11 Ref: https://github.com/openwrt/openwrt/issues/5411
  12
  13 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  14 ---
  15 --- a/drivers/net/ethernet/marvell/mvneta.c
  16 +++ b/drivers/net/ethernet/marvell/mvneta.c
  17 @@ -5233,6 +5233,16 @@ static int mvneta_setup_tc(struct net_de
  18         }
  19  }
  20
  21 +#ifndef CONFIG_ARM64
  22 +static u16 mvneta_select_queue(struct net_device *dev, struct sk_buff *skb,
  23 +                              struct net_device *sb_dev)
  24 +{
  25 +       /* XXX: hardware queue scheduling is broken,
  26 +        * use only one queue until it is fixed */
  27 +       return 0;
  28 +}
  29 +#endif
  30 +
  31  static const struct net_device_ops mvneta_netdev_ops = {
  32         .ndo_open            = mvneta_open,
  33         .ndo_stop            = mvneta_stop,
  34 @@ -5243,6 +5253,9 @@ static const struct net_device_ops mvnet
  35         .ndo_fix_features    = mvneta_fix_features,
  36         .ndo_get_stats64     = mvneta_get_stats64,
  37         .ndo_eth_ioctl        = mvneta_ioctl,
  38 +#ifndef CONFIG_ARM64
  39 +       .ndo_select_queue    = mvneta_select_queue,
  40 +#endif
  41         .ndo_bpf             = mvneta_xdp,
  42         .ndo_xdp_xmit        = mvneta_xdp_xmit,
  43         .ndo_setup_tc        = mvneta_setup_tc,