This is a note to let you know that I've just added the patch titled [PATCH stable 5.9 05/24] mlx4: handle non-napi callers to napi_poll to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mlx4-handle-non-napi-callers-to-napi_poll.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Oct 17 08:52:03 AM CEST 2020 From: Jonathan Lemon <bsd@xxxxxx> Date: Thu, 8 Oct 2020 11:45:26 -0700 Subject: [PATCH stable 5.9 05/24] mlx4: handle non-napi callers to napi_poll From: Jonathan Lemon <bsd@xxxxxx> [ 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.lemon@xxxxxxxxx> Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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); Patches currently in stable-queue which might be from bsd@xxxxxx are queue-5.9/mlx4-handle-non-napi-callers-to-napi_poll.patch