commit 0b72e02a1fee3e383fad0aa2e7e5cf8c6a06c6bf
Author: Devesh Sharma <devesh.sharma@broadcom.com>
Date:   Wed Jan 31 01:28:53 2018 -0500

    libbnxt_re: Fix lat test failure in event mode
    
    The application assumes that, when CQ is armed, it gives interrupt
    for the new CQEs generated and not for the existing CQEs. This is
    in-line with the IB-Spec. However, Broadcom HW generates an interrupt
    for any unread CQEs not just new ones. This results in a scenario
    where the application is expecting a completion for a SEND operation
    but it receives a completion for a prior incoming-send/RQE that was
    not yet consumed as per the HW thereby leading to failure.
    Workaround this by deferring the ARM-ing of the CQ when invoked in
    the notify_cq hook to 'poll_cq' so that the CQ is armed after all
    completions are consumed.
    
    Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
    Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
    Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>

diff --git a/providers/bnxt_re/main.h b/providers/bnxt_re/main.h
index affe24f0..08aa277d 100644
--- a/providers/bnxt_re/main.h
+++ b/providers/bnxt_re/main.h
@@ -76,6 +76,9 @@ struct bnxt_re_cq {
 	struct list_head rfhead;
 	uint32_t cqe_size;
 	uint8_t  phase;
+	int deferred_arm_flags;
+	bool first_arm;
+	bool deferred_arm;
 };
 
 struct bnxt_re_srq {
diff --git a/providers/bnxt_re/verbs.c b/providers/bnxt_re/verbs.c
index 09ac3335..2e88304c 100644
--- a/providers/bnxt_re/verbs.c
+++ b/providers/bnxt_re/verbs.c
@@ -202,6 +202,7 @@ struct ibv_cq *bnxt_re_create_cq(struct ibv_context *ibvctx, int ncqe,
 	cq->phase = resp.phase;
 	cq->cqq.tail = resp.tail;
 	cq->udpi = &cntx->udpi;
+	cq->first_arm = true;
 
 	list_head_init(&cq->sfhead);
 	list_head_init(&cq->rfhead);
@@ -654,6 +655,11 @@ int bnxt_re_poll_cq(struct ibv_cq *ibvcq, int nwc, struct ibv_wc *wc)
 
 	pthread_spin_lock(&cq->cqq.qlock);
 	dqed = bnxt_re_poll_one(cq, nwc, wc);
+	if (cq->deferred_arm) {
+		bnxt_re_ring_cq_arm_db(cq, cq->deferred_arm_flags);
+		cq->deferred_arm = false;
+		cq->deferred_arm_flags = 0;
+	}
 	pthread_spin_unlock(&cq->cqq.qlock);
 	/* Check if anything is there to flush. */
 	pthread_spin_lock(&cntx->fqlock);
@@ -718,7 +724,12 @@ int bnxt_re_arm_cq(struct ibv_cq *ibvcq, int flags)
 	pthread_spin_lock(&cq->cqq.qlock);
 	flags = !flags ? BNXT_RE_QUE_TYPE_CQ_ARMALL :
 			 BNXT_RE_QUE_TYPE_CQ_ARMSE;
-	bnxt_re_ring_cq_arm_db(cq, flags);
+	if (cq->first_arm) {
+		bnxt_re_ring_cq_arm_db(cq, flags);
+		cq->first_arm = false;
+	}
+	cq->deferred_arm = true;
+	cq->deferred_arm_flags = flags;
 	pthread_spin_unlock(&cq->cqq.qlock);
 
 	return 0;