Hi,
DEVX API is the modern way to utilize direct access to HCA. More info - GitHub - Mellanox/devx. Mellanox OFED version 5.x use it.
Check your device status - it is down and in pulling state. Assuming you are working in InfiniBand mode, you need running Subnet Manager on the fabric.
If the node connected to Ethernet fabric/switch, convert the port to Ethernet using mlxconfig command. Check Mellanox OFED user manual and MFT ( Mellanox Firmware Tools) manuals for additional info.
#mlxconfig -d /dev/mst/mt4119_pciconf0 s LINK_TYPE_<1|2>=2
If you are using bonding , undo the configuration and start with a single port.
Another good think that you can do is to recompile DPDK with debugging information and trace failure to the line in the code and go from there. To add debug information to DPDK, use meson —buildtype=debug parameters. For additional info, check DPDK documentation.