[PATCH 3.18 112/145] net/mlx4_en: Fix bad WQE issue

Greg Kroah-Hartman
2017-04-16T10:59:09Z

From: Eugenia Emantayev <eugenia@mellanox.com>

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>

---
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -438,8 +438,14 @@ int mlx4_en_activate_rx_rings(struct mlx
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;