[openib-general] Completion callback /teardown race

[Eric Barton]

Or,

> Eric Barton wrote:
> > I create 1 CQ just for receive completions on each of my QPs.  When I
tear down
> > the QP, I rdma_disconnect(), change the QP state to IB_QPS_ERR and then
wait
> > for all currently posted receives to complete.
> 
> I understand your driver is a CMA consumer whose QP state transitions 
> are carried out by the CMA. So you need ***not*** modify the QP state to 
> error, as the CMA does it for you in rdma_disconnect() before sending 
> the DREQ or DREP.

Yes - understood.  It's not actually harmful at this point I think.  Please
correct me if I'm wrong.

> Please note that you need to call rdma_disconnect() in both sides, the 
> one that initiates the disconnection but also on the side that gets the 
> DREQ, that is suddenly gets RDMA_CM_EVENT_DISCONNECTED event...

I ensure I always call rdma_disconnect() once, no matter whether I am the
initiator or not.

                Cheers,
                        Eric