This is a note to let you know that I've just added the patch titled

iw_cxgb4: only insert drain cqes if wq is flushed

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: iw_cxgb4-only-insert-drain-cqes-if-wq-is-flushed.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From c058ecf6e455fac7346d46197a02398ead90851f Mon Sep 17 00:00:00 2001

From: Steve Wise swise@opengridcomputing.com Date: Mon, 27 Nov 2017 13:16:32 -0800 Subject: iw_cxgb4: only insert drain cqes if wq is flushed

From: Steve Wise swise@opengridcomputing.com

commit c058ecf6e455fac7346d46197a02398ead90851f upstream.

Only insert our special drain CQEs to support ib_drain_sq/rq() after the wq is flushed. Otherwise, existing but not yet polled CQEs can be returned out of order to the user application. This can happen when the QP has exited RTS but not yet flushed the QP, which can happen during a normal close (vs abortive close).

In addition never count the drain CQEs when determining how many CQEs need to be synthesized during the flush operation. This latter issue should never happen if the QP is properly flushed before inserting the drain CQE, but I wanted to avoid corrupting the CQ state. So we handle it and log a warning once.

Fixes: 4fe7c2962e11 ("iw_cxgb4: refactor sq/rq drain logic") Signed-off-by: Steve Wise swise@opengridcomputing.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/infiniband/hw/cxgb4/cq.c | 5 +++++ drivers/infiniband/hw/cxgb4/qp.c | 14 ++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/cxgb4/cq.c +++ b/drivers/infiniband/hw/cxgb4/cq.c @@ -410,6 +410,11 @@ next_cqe:

static int cqe_completes_wr(struct t4_cqe *cqe, struct t4_wq *wq) { + if (CQE_OPCODE(cqe) == C4IW_DRAIN_OPCODE) { + WARN_ONCE(1, "Unexpected DRAIN CQE qp id %u!\n", wq->sq.qid); + return 0; + } + if (CQE_OPCODE(cqe) == FW_RI_TERMINATE) return 0;

--- a/drivers/infiniband/hw/cxgb4/qp.c +++ b/drivers/infiniband/hw/cxgb4/qp.c @@ -868,7 +868,12 @@ int c4iw_post_send(struct ib_qp *ibqp, s

qhp = to_c4iw_qp(ibqp); spin_lock_irqsave(&qhp->lock, flag); - if (t4_wq_in_error(&qhp->wq)) { + + /* + * If the qp has been flushed, then just insert a special + * drain cqe. + */ + if (qhp->wq.flushed) { spin_unlock_irqrestore(&qhp->lock, flag); complete_sq_drain_wr(qhp, wr); return err; @@ -1012,7 +1017,12 @@ int c4iw_post_receive(struct ib_qp *ibqp

qhp = to_c4iw_qp(ibqp); spin_lock_irqsave(&qhp->lock, flag); - if (t4_wq_in_error(&qhp->wq)) { + + /* + * If the qp has been flushed, then just insert a special + * drain cqe. + */ + if (qhp->wq.flushed) { spin_unlock_irqrestore(&qhp->lock, flag); complete_rq_drain_wr(qhp, wr); return err;

Patches currently in stable-queue which might be from swise@opengridcomputing.com are

queue-4.14/iw_cxgb4-only-insert-drain-cqes-if-wq-is-flushed.patch