[ofa-general] synchronize commands issued to MTHCA

[Roland Dreier]

 > The SW2HW_MPT command is issued while UDAV table is been creating. During 
 > the time that the driver is waiting for the completion of the command, it 
 > does many other things: creating send mad package, posting send mad 
 > request to the SQ and posting another receive mad request to the RQ. 
 > There's no error report for all of these actions. However after it, the 
 > HCA report command parameter error for the SW2HW_MPT.

I doubt the problem is creating the UD address vector -- that is just
shuffling some things around in the CPU's memory.  It seems more
likely that posting a send or receive request is messing things up
somehow.  What is the call chain that calls SW2HW_MPT in this case?
Also are you going through the mthca_cmd_post_dbell() or mthca_cmd_post_hcr()
code to write the command params to the HCA?

I think the best way to debug this would be to work directly with
Mellanox to get a debug build of the HCA firmware and get definite
info on why the SW2HW_MPT command is failing.

 - R.