[ofa-general] [PATCH 1/2] IB/ipath - fix lost UD send work request

[Ralph Campbell]

If a UD QP has some work requests queued to be sent by the DMA engine
followed by a local loopback work request, we have to wait for
the previous work requests to finish or the completion for the
local loopback work request would be generated out of order. The
problem was that the work request queue pointer was already updated
so that the request would not be processed when the DMA queue drained.
		        
Signed-off-by: Ralph Campbell <ralph.campbell at qlogic.com>
---

 drivers/infiniband/hw/ipath/ipath_ud.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/ipath/ipath_ud.c b/drivers/infiniband/hw/ipath/ipath_ud.c
index 36aa242..729446f 100644
--- a/drivers/infiniband/hw/ipath/ipath_ud.c
+++ b/drivers/infiniband/hw/ipath/ipath_ud.c
@@ -267,6 +267,7 @@ int ipath_make_ud_req(struct ipath_qp *qp)
 	u16 lrh0;
 	u16 lid;
 	int ret = 0;
+	int next_cur;
 
 	spin_lock_irqsave(&qp->s_lock, flags);
 
@@ -290,8 +291,9 @@ int ipath_make_ud_req(struct ipath_qp *qp)
 		goto bail;
 
 	wqe = get_swqe_ptr(qp, qp->s_cur);
-	if (++qp->s_cur >= qp->s_size)
-		qp->s_cur = 0;
+	next_cur = qp->s_cur + 1;
+	if (next_cur >= qp->s_size)
+		next_cur = 0;
 
 	/* Construct the header. */
 	ah_attr = &to_iah(wqe->wr.wr.ud.ah)->attr;
@@ -315,6 +317,7 @@ int ipath_make_ud_req(struct ipath_qp *qp)
 				qp->s_flags |= IPATH_S_WAIT_DMA;
 				goto bail;
 			}
+			qp->s_cur = next_cur;
 			spin_unlock_irqrestore(&qp->s_lock, flags);
 			ipath_ud_loopback(qp, wqe);
 			spin_lock_irqsave(&qp->s_lock, flags);
@@ -323,6 +326,7 @@ int ipath_make_ud_req(struct ipath_qp *qp)
 		}
 	}
 
+	qp->s_cur = next_cur;
 	extra_bytes = -wqe->length & 3;
 	nwords = (wqe->length + extra_bytes) >> 2;