IB/mlx4: Initialize send queue entry ownership bits

We need to initialize the owner bit of send queue WQEs to hardware
ownership whenever the QP is modified from reset to init, not just
when the QP is first allocated.  This avoids having the hardware
process stale WQEs when the QP is moved to reset but not destroyed and
then modified to init again.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 88a994d..dc137de 100644 (file)
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -270,9 +270,7 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
                            struct ib_qp_init_attr *init_attr,
                            struct ib_udata *udata, int sqpn, struct mlx4_ib_qp *qp)
 {
-       struct mlx4_wqe_ctrl_seg *ctrl;
        int err;
-       int i;
 
        mutex_init(&qp->mutex);
        spin_lock_init(&qp->sq.lock);
@@ -352,11 +350,6 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
                if (err)
                        goto err_mtt;
 
-               for (i = 0; i < qp->sq.max; ++i) {
-                       ctrl = get_send_wqe(qp, i);
-                       ctrl->owner_opcode = cpu_to_be32(1 << 31);
-               }
-
                qp->sq.wrid  = kmalloc(qp->sq.max * sizeof (u64), GFP_KERNEL);
                qp->rq.wrid  = kmalloc(qp->rq.max * sizeof (u64), GFP_KERNEL);
 
@@ -878,6 +871,21 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
        else
                sqd_event = 0;
 
+       /*
+        * Before passing a kernel QP to the HW, make sure that the
+        * ownership bits of the send queue are set so that the
+        * hardware doesn't start processing stale work requests.
+        */
+       if (!ibqp->uobject && cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT) {
+               struct mlx4_wqe_ctrl_seg *ctrl;
+               int i;
+
+               for (i = 0; i < qp->sq.max; ++i) {
+                       ctrl = get_send_wqe(qp, i);
+                       ctrl->owner_opcode = cpu_to_be32(1 << 31);
+               }
+       }
+
        err = mlx4_qp_modify(dev->dev, &qp->mtt, to_mlx4_state(cur_state),
                             to_mlx4_state(new_state), context, optpar,
                             sqd_event, &qp->mqp);