net/mlx4_en: Fix bad WQE issue

commit 6496bbf0ec481966ef9ffe5b6660d8d1b55c60cc upstream.

Single send WQE in RX buffer should be stamped with software
ownership in order to prevent the flow of QP in error in FW
once UPDATE_QP is called.

Fixes: 9f519f68cfff ('mlx4_en: Not using Shared Receive Queues')
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 28a4b34..82bf1b5 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -439,8 +439,14 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
                ring->cqn = priv->rx_cq[ring_ind]->mcq.cqn;
 
                ring->stride = stride;
-               if (ring->stride <= TXBB_SIZE)
+               if (ring->stride <= TXBB_SIZE) {
+                       /* Stamp first unused send wqe */
+                       __be32 *ptr = (__be32 *)ring->buf;
+                       __be32 stamp = cpu_to_be32(1 << STAMP_SHIFT);
+                       *ptr = stamp;
+                       /* Move pointer to start of rx section */
                        ring->buf += TXBB_SIZE;
+               }
 
                ring->log_stride = ffs(ring->stride) - 1;
                ring->buf_size = ring->size * ring->stride;