new file mode 100644
@@ -0,0 +1,46 @@
+From: Sven Eckelmann <sven@narfation.org>
+Date: Tue, 9 Jun 2020 14:08:44 +0200
+Subject: essedma: Disable TCP segmentation offload for IPv6
+
+It was noticed that the the whole MAC can hang when transferring data from
+one ar40xx port (WAN ports) to the CPU and from the CPU back to another
+ar40xx port (LAN ports). The CPU was doing only NATing in that process.
+
+Usually, the problem first starts with a simple data corruption:
+
+ $ wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-10.4.0-amd64-netinst.iso -O /dev/null
+ ...
+ Connecting to saimei.ftp.acc.umu.se (saimei.ftp.acc.umu.se)|2001:6b0:19::138|:443... connected.
+ ...
+ Read error at byte 48807936/352321536 (Decryption has failed.). Retrying.
+
+But after a short while, the whole MAC will stop to react. No traffic can
+be transported anymore from the CPU port from/to the AR40xx PHY/switch and
+the MAC has to be resetted.
+
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+--- a/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
++++ b/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
+@@ -970,17 +970,14 @@ static int edma_axi_probe(struct platfor
+ edma_netdev[i]->features = NETIF_F_HW_CSUM | NETIF_F_RXCSUM
+ | NETIF_F_HW_VLAN_CTAG_TX
+ | NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_SG |
+- NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_GRO;
++ NETIF_F_TSO | NETIF_F_GRO;
+ edma_netdev[i]->hw_features = NETIF_F_HW_CSUM | NETIF_F_RXCSUM |
+ NETIF_F_HW_VLAN_CTAG_RX
+- | NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6 |
+- NETIF_F_GRO;
++ | NETIF_F_SG | NETIF_F_TSO | NETIF_F_GRO;
+ edma_netdev[i]->vlan_features = NETIF_F_HW_CSUM | NETIF_F_SG |
+- NETIF_F_TSO | NETIF_F_TSO6 |
+- NETIF_F_GRO;
++ NETIF_F_TSO | NETIF_F_GRO;
+ edma_netdev[i]->wanted_features = NETIF_F_HW_CSUM | NETIF_F_SG |
+- NETIF_F_TSO | NETIF_F_TSO6 |
+- NETIF_F_GRO;
++ NETIF_F_TSO | NETIF_F_GRO;
+
+ #ifdef CONFIG_RFS_ACCEL
+ edma_netdev[i]->features |= NETIF_F_RXHASH | NETIF_F_NTUPLE;
It was noticed that the the whole MAC can hang when transferring data from one ar40xx port (WAN ports) to the CPU and from the CPU back to another ar40xx port (LAN ports). The CPU was doing only NATing in that process. Usually, the problem first starts with a simple data corruption: $ wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-10.4.0-amd64-netinst.iso -O /dev/null ... Connecting to saimei.ftp.acc.umu.se (saimei.ftp.acc.umu.se)|2001:6b0:19::138|:443... connected. ... Read error at byte 48807936/352321536 (Decryption has failed.). Retrying. But after a short while, the whole MAC will stop to react. No traffic can be transported anymore from the CPU port from/to the AR40xx PHY/switch and the MAC has to be resetted. Signed-off-by: Sven Eckelmann <sven@narfation.org> --- The problem was first observed on OpenWrt 18.06 and OpenWrt 19.07. It would be good that this patch (or maybe even a better one) is copied to these versions (and then refreshed). Thanks ...le-TCP-segmentation-offload-for-IPv6.patch | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 target/linux/ipq40xx/patches-5.4/712-essedma-Disable-TCP-segmentation-offload-for-IPv6.patch