IB/hfi1: Add additional checks when handling TID RDMA READ RESP packet

commit a8adbf7d0d0a6e3bf7f99da461a06039364e028b upstream.

In a congested fabric with adaptive routing enabled, traces show that
packets could be delivered out of order, which could cause incorrect
processing of stale packets. For stale TID RDMA READ RESP packets that
cause KDETH EFLAGS errors, this patch adds additional checks before
processing the packets.

Fixes: 9905bf06e890 ("IB/hfi1: Add functions to receive TID RDMA READ response")
Cc: <stable@vger.kernel.org>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Link: https://lore.kernel.org/r/20190815192045.105923.59813.stgit@awfm-01.aw.intel.com
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index 6d1e34282e00eeab2aa93ff06c8b80e566a3268d..3ed5a1530c2ca50148e56a89da0c1dd27423689d 100644 (file)
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -2742,9 +2742,12 @@ static bool handle_read_kdeth_eflags(struct hfi1_ctxtdata *rcd,
 
                wqe = do_rc_completion(qp, wqe, ibp);
                if (qp->s_acked == qp->s_tail)
-                       break;
+                       goto s_unlock;
        }
 
+       if (qp->s_acked == qp->s_tail)
+               goto s_unlock;
+
        /* Handle the eflags for the request */
        if (wqe->wr.opcode != IB_WR_TID_RDMA_READ)
                goto s_unlock;