Loopback issue with Zynq FPGA running Linux 4.14


we are using Connectx-5 card on Xilinx FPGA board Fidus-Sidewinder100, with Zynq Ultrascale+ device.

Which is running linux version 4.14, and mellanox drivers from this repo:

https://github.com/Xilinx/linux-xlnx/tree/master/drivers/net/ethernet/mellanox https://github.com/Xilinx/linux-xlnx/tree/master/drivers/net/ethernet/mellanox .

And we are using Mobiveil’s PCIe GPEX RC running following RC driver :

https://github.com/torvalds/linux/blob/master/drivers/pci/controller/pcie-mobiveil.c https://github.com/torvalds/linux/blob/master/drivers/pci/controller/pcie-mobiveil.c

please help us solving following queries.

1. we tried connecting a qsft cable on loop-back mode and ping with namespaces configured. Ping never succeeds. And ethtool stats shows multiple wqe_err incremented.

commands :



ip netns add ns1

ip link set dev $eth0 netns ns1

ip netns exec ns1 ip addr add dev $eth0

ip netns exec ns1 ifconfig $eth0 mtu 9600

ip netns exec ns1 ifconfig $eth0 up

sleep 5

ifconfig $eth1 mtu 9600

ifconfig $eth1

sleep 5


2. Next we ran ethtool selftest with external loopback test on eth0 we see one wqe_err set and with all other test passing loopback failed with flags set to 7.


ethtool -t $eth0 external_lb

3. After googling around we found this patch : https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1799393 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1799393

is this patch relevant to this issue? if yes is there any way we can backport this patch to 4.14 kernel’s Mellanox driver ?

4. Petalinux for Xilinx do not have Mellanox Firmware Tools, https://github.com/Mellanox https://github.com/Mellanox doesn’t seems to have MFT source either,

can we get cross-compilable MFT source which is compatible with the following repo ?

https://github.com/Xilinx/linux-xlnx/tree/master/drivers/net/ethernet/mellanox https://github.com/Xilinx/linux-xlnx/tree/master/drivers/net/ethernet/mellanox

same test seems to be working fine on a standard ASUS motherboard, running the same version of Mellanox driver and Linux kernel.


Hi Subrahmanya,

Thank you for posting your question on the Mellanox Community.

Based on the information provided support for this product needs to be obtained through Xilinx.

Thanks and regards,

~Mellanox Technical Support