[ofw] [Patch 4/62] Reference implementation of NDv2

[Fab Tillier]

QP state checks when posting aren't really accomplishing anything.  The SQ check especially only checks against the QP being in RST, while a proper check would be to prevent posting until in RTS.  However, the QP state is decoupled between the hardware and the software, so a QP can move to RTS before user-mode detects it, and a receive completion can imply RTS.  Fixing the state checks to be useful is *really hard*, so this patch just removes them (fewer branches in post path).

Signed-off-by: Fab Tillier <ftillier at microsoft.com>

diff -dwup3 -x *svn* -r c:\dev\openib\ofw\gen1\branches\mlx4_30\trunk\hw\mlx4\user\hca\qp.c .\hw\mlx4\user\hca\qp.c
--- c:\dev\openib\ofw\gen1\branches\mlx4_30\trunk\hw\mlx4\user\hca\qp.c	Thu Mar 29 00:15:30 2012
+++ .\hw\mlx4\user\hca\qp.c	Wed May 23 18:40:41 2012
@@ -230,14 +230,6 @@ mlx4_post_send(
 
 	pthread_spin_lock(&qp->sq.lock);
 
-	/* XXX check that state is OK to post send */
-	if(ibqp->state == IBV_QPS_RESET) {
-		status = IB_INVALID_QP_STATE;
-		if (bad_wr)
-			*bad_wr = wr;
-		goto err_state;
-	}
-
 	ind = qp->sq.head;
 
 	for (nreq = 0; wr; ++nreq, wr = wr->p_next) {
@@ -478,7 +470,6 @@ out:
 		stamp_send_wqe(qp, (ind + qp->sq_spare_wqes - 1) &
 			       (qp->sq.wqe_cnt - 1));
 
-err_state:
 	pthread_spin_unlock(&qp->sq.lock);
 
 	return status;
@@ -501,14 +492,6 @@ mlx4_post_recv(
 
 	pthread_spin_lock(&qp->rq.lock);
 
-	/* XXX check that state is OK to post receive */
-	if(qp->ibv_qp.state == IBV_QPS_RESET) {
-		status = IB_INVALID_QP_STATE;
-		if (bad_wr)
-			*bad_wr = wr;
-		goto err_state;
-	}
-
 	ind = qp->rq.head & (qp->rq.wqe_cnt - 1);
 
 	for (nreq = 0; wr; ++nreq, wr = wr->p_next) {
@@ -558,7 +541,6 @@ out:
 		*qp->db = htonl(qp->rq.head & 0xffff);
 	}
 
-err_state:
 	pthread_spin_unlock(&qp->rq.lock);
 
 	return status;
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