Revert "mvebu: remove linux 4.4 support"

[openwrt/openwrt.git] / target / linux / mvebu / patches-4.4 / 400-mvneta-tx-queue-workaround.patch

diff --git a/target/linux/mvebu/patches-4.4/400-mvneta-tx-queue-workaround.patch b/target/linux/mvebu/patches-4.4/400-mvneta-tx-queue-workaround.patch
new file mode 100644 (file)
index 0000000..5dba311
--- /dev/null
+++ b/target/linux/mvebu/patches-4.4/400-mvneta-tx-queue-workaround.patch
@@ -0,0 +1,36 @@
+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
+@@ -3984,6 +3984,16 @@ 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,
++                             void *accel_priv,
++                             select_queue_fallback_t fallback)
++{
++      /* 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,
+@@ -3994,6 +4004,7 @@ 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,
+ };
+ 
+ const struct ethtool_ops mvneta_eth_tool_ops = {