6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li RongQing [ Upstream commit b056ca4d3742d0769f91137bb1ce3215428398f7 ] mlx5e_poll_ico_cq() requires sq->cc to be updated only after mlx5_cqwq_update_db_record(), otherwise a CQ overrun may occur. The current implementation updates sq->cc before the CQ doorbell record, violating this ordering requirement. Update the CQ doorbell record first and use dma_wmb() before updating sq->cc. This ensures that the CQ space is released to the device before the corresponding ICOSQ consumer index is updated by software. Fixes: fd9b4be8002c ("net/mlx5e: RX, Support multiple outstanding UMR posts") Signed-off-by: Li RongQing Reviewed-by: Dragos Tatulea Signed-off-by: Tariq Toukan Reviewed-by: Daniel Machon Link: https://patch.msgid.link/20261006105820.257208-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index e688ce9d383c5..6fced90cae604 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -1079,10 +1079,12 @@ int mlx5e_poll_ico_cq(struct mlx5e_cq *cq) } while (!last_wqe); } while ((++i < MLX5E_TX_CQ_POLL_BUDGET) && (cqe = mlx5_cqwq_get_cqe(&cq->wq))); - sq->cc = sqcc; - mlx5_cqwq_update_db_record(&cq->wq); + /* ensure cq space is freed before enabling more cqes */ + dma_wmb(); + + sq->cc = sqcc; return i; } -- 2.53.0