The HP service pack for proliant should flash them to stock OEM firmware.Since these cards seem to be selling for awesome prices: 649281-B21 656089-001 661685-001 HP IB FDR/EN 10/40GB 2P 544QSFP ADAPTER | eBay
I wanted to ask @i386 and others what files you used to flash these particular HP adapters.
Instructions are here Flash OEM (IBM) Mellanox ConnectX-3 EN with stock firmware? but the old firmware links are not working.
For the most recent firmware release, here is a link:
Firmware for 649281-B21
Click 'Revision History' to verify that the most recent release is shown.