HP Smart Array 6400 Series Controllers in PowerEdge 2950

An answer in this forum from several years indicated that it is possible to use an HP Smart Array 6400 Series Controller in a PowerEdge server, as long as it is used as a secondary controller.  I am trying to installl two Smart Array controllers as secondary controllers.  Although my PowerEdge 2950 server recognizes the controllers, and I can access and use the ROM-based controller RAID configuration utility, the system hangs after reporting the controller status.  Is anyone using this combination of hardware successfully?  Thanks for your help.

Alan