iw_cxgb4: handle draining an idle qp
In c4iw_drain_sq/rq(), if the particular queue is already empty
then don't block.
Fixes: ce4af14d94aa ('iw_cxgb4: add queue drain functions')
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index e17fb5d5..8aa2e52 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -1895,13 +1895,27 @@
void c4iw_drain_sq(struct ib_qp *ibqp)
{
struct c4iw_qp *qp = to_c4iw_qp(ibqp);
+ unsigned long flag;
+ bool need_to_wait;
- wait_for_completion(&qp->sq_drained);
+ spin_lock_irqsave(&qp->lock, flag);
+ need_to_wait = !t4_sq_empty(&qp->wq);
+ spin_unlock_irqrestore(&qp->lock, flag);
+
+ if (need_to_wait)
+ wait_for_completion(&qp->sq_drained);
}
void c4iw_drain_rq(struct ib_qp *ibqp)
{
struct c4iw_qp *qp = to_c4iw_qp(ibqp);
+ unsigned long flag;
+ bool need_to_wait;
- wait_for_completion(&qp->rq_drained);
+ spin_lock_irqsave(&qp->lock, flag);
+ need_to_wait = !t4_rq_empty(&qp->wq);
+ spin_unlock_irqrestore(&qp->lock, flag);
+
+ if (need_to_wait)
+ wait_for_completion(&qp->rq_drained);
}