If the HCA connects to a switch, using the same cable (assuming compatible), proceed with a loop back connection from port 1 to port 2 and check if the link comes up.
If the link comes up, proceed with the same test but this time between two ports from the switch and validate the link comes up.
You can also review the /var/log/messages for any errors/warnings and/or anomalies.
The card was installed in the third PCIe slot. The cable was 10Gbps. Yesterday, one of my co-worker replaced the 10Gbps one with the 25Gbps cable, then things become to work. It seems the switch has configured with 25Gbps cable. I didn’t know too much about switch, so I do not touch this side.
Also, do note (based on the screen capture above) that the card is at Ethernet mode. If you need InfiniBand support, you need to change the port type to IB.
You will need to install MFT (or in case you have MOFED it is already there) and use: /sbin/connectx_port_config