[openib-general] optional function calls

[Sean Hefty]

I'm trying to decide which IB function require checks to see if they exist.  Should we go by the spec and assume that all mandatory functions are implemented by the device driver?  Or should we allow the minimal subset possible?  Also, if calls like ib_create_srq and ib_attach_mcast check to see if the device implemented the functions, do we need the same check on calls to ib_destroy_srq and ib_detach_mcast?  I.e. should we only perform the check in the creation calls?

- Sean