mvebu: sort patches
[openwrt/openwrt.git] / target / linux / mvebu / patches-5.4 / 700-mvneta-tx-queue-workaround.patch
diff --git a/target/linux/mvebu/patches-5.4/700-mvneta-tx-queue-workaround.patch b/target/linux/mvebu/patches-5.4/700-mvneta-tx-queue-workaround.patch
new file mode 100644 (file)
index 0000000..a82a4c0
--- /dev/null
@@ -0,0 +1,34 @@
+The hardware queue scheduling is apparently configured with fixed
+priorities, which creates a nasty fairness issue where traffic from one
+CPU can starve traffic from all other CPUs.
+
+Work around this issue by forcing all tx packets to go through one CPU,
+until this issue is fixed properly.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+--- a/drivers/net/ethernet/marvell/mvneta.c
++++ b/drivers/net/ethernet/marvell/mvneta.c
+@@ -4684,6 +4684,14 @@ static int mvneta_ethtool_set_eee(struct
+       return phylink_ethtool_set_eee(pp->phylink, eee);
+ }
++static u16 mvneta_select_queue(struct net_device *dev, struct sk_buff *skb,
++                             struct net_device *sb_dev)
++{
++      /* XXX: hardware queue scheduling is broken,
++       * use only one queue until it is fixed */
++      return 0;
++}
++
+ static const struct net_device_ops mvneta_netdev_ops = {
+       .ndo_open            = mvneta_open,
+       .ndo_stop            = mvneta_stop,
+@@ -4694,6 +4702,7 @@ static const struct net_device_ops mvnet
+       .ndo_fix_features    = mvneta_fix_features,
+       .ndo_get_stats64     = mvneta_get_stats64,
+       .ndo_do_ioctl        = mvneta_ioctl,
++      .ndo_select_queue    = mvneta_select_queue,
+       .ndo_bpf             = mvneta_xdp,
+       .ndo_xdp_xmit        = mvneta_xdp_xmit,
+ };