IB/rxe: increment msn only when completing a request

According to C9-147, MSN should only be incremented when the last packet of
a multi packet request has been received.

"Logically, the requester associates a sequential Send Sequence Number
(SSN) with each WQE posted to the send queue. The SSN bears a one-
to-one relationship to the MSN returned by the responder in each re-
sponse packet. Therefore, when the requester receives a response, it in-
terprets the MSN as representing the SSN of the most recent request
completed by the responder to determine which send WQE(s) can be
completed."

Fixes: 8700e3e7c485 ("Soft RoCE driver")

Signed-off-by: David Marchand <david.marchand@6wind.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index d404a8aba7af..c9dd385ce62e 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -813,18 +813,17 @@ static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
                 WARN_ON_ONCE(1);
         }
 
-        /* We successfully processed this new request. */
-        qp->resp.msn++;
-
         /* next expected psn, read handles this separately */
         qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
 
         qp->resp.opcode = pkt->opcode;
         qp->resp.status = IB_WC_SUCCESS;
 
-        if (pkt->mask & RXE_COMP_MASK)
+        if (pkt->mask & RXE_COMP_MASK) {
+                /* We successfully processed this new request. */
+                qp->resp.msn++;
                 return RESPST_COMPLETE;
-        else if (qp_type(qp) == IB_QPT_RC)
+        } else if (qp_type(qp) == IB_QPT_RC)
                 return RESPST_ACKNOWLEDGE;
         else
                 return RESPST_CLEANUP;