Stop openibd
Turn debug on for udev.
udevadm control --log-priority debug
udevadm control --reload-rules
Start openibd
And search for 90-ib.rules in /var/log/messages
These are logs when it works, but you should see errors that can give use some clues
Jan 6 23:08:40 my-host udevd-work[11143]: MODE 0666 /etc/udev/rules.d/90-ib.rules:3
Jan 6 23:08:40 my-host udevd-work[11143]: NAME 'infiniband/ucm0' /etc/udev/rules.d/90-ib.rules:3
Jan 6 23:08:40 my-host udevd-work[11143]: create db link (infiniband/ucm0 char/231:224)
Jan 6 23:08:40 my-host udevd-work[11143]: creating device node '/dev/infiniband/ucm0', devnum=231:224, mode=0666, uid=0, gid=0
Jan 6 23:08:40 my-host udevd-work[11143]: preserve file '/dev/infiniband/ucm0', because it has correct dev_t
Jan 6 23:08:40 my-host udevd-work[11143]: preserve permissions /dev/infiniband/ucm0, 020666, uid=0, gid=0
Jan 6 23:08:40 my-host udevd-work[11143]: creating symlink '/dev/char/231:224' to '../infiniband/ucm0'