[PATCH 5.9 005/757] mlx4: handle non-napi callers to napi_poll

[Greg Kroah-Hartman]

From: Jonathan Lemon <b...@fb.com>

[ Upstream commit b2b8a92733b288128feb57ffa694758cf475106c ]

netcons calls napi_poll with a budget of 0 to transmit packets.
Handle this by:
 - skipping RX processing
 - do not try to recycle TX packets to the RX cache

Signed-off-by: Jonathan Lemon <jonathan.le...@gmail.com>
Reviewed-by: Tariq Toukan <tar...@nvidia.com>
Signed-off-by: Jakub Kicinski <k...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c |    3 +++
 drivers/net/ethernet/mellanox/mlx4/en_tx.c |    2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -943,6 +943,9 @@ int mlx4_en_poll_rx_cq(struct napi_struc
        bool clean_complete = true;
        int done;
 
+       if (!budget)
+               return 0;
+
        if (priv->tx_ring_num[TX_XDP]) {
                xdp_tx_cq = priv->tx_cq[TX_XDP][cq->ring];
                if (xdp_tx_cq->xdp_busy) {
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -350,7 +350,7 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_
                .dma = tx_info->map0_dma,
        };
 
-       if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
+       if (!napi_mode || !mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
                dma_unmap_page(priv->ddev, tx_info->map0_dma,
                               PAGE_SIZE, priv->dma_dir);
                put_page(tx_info->page);