From 05b54bf0892dcd1e3698ba86a297722b7566cc10 Mon Sep 17 00:00:00 2001 From: Yajun Wu Date: Mon, 14 Feb 2022 08:03:19 +0200 Subject: [PATCH] common/mlx5: fix queue pair ack timeout configuration MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit VDPA driver creates two QPs(1 queue pair include 1 send queue and 1 receive queue) per virtio queue to get traffic events from NIC to SW. Two QPs(called FW QP and SW QP) are created as loopback QP and FW QP'SQ is connected to SW QP'RQ internally. When packet receive or send out, HW will send WQE by FW QP'SQ, then SW will get CQE from the CQ of SW QP. With large scale and heavy traffic, the SQ's request may fail to get ACK from RQ HW, because HW is busy. SQ will retry the request with qpc.retry_count times and each time wait for 4.096 uS *2^(ack_timeout) for the response. If still can’t get RQ’s HW response, SQ will go to an error state. 16 is experienced value. It should not be too high or too low. Too high will make QP waits too long in case it’s packet drop. Too low will cause QP to go to an error state(retry-exceeded) easily. Fixes: 15c3807e86ab ("common/mlx5: support DevX QP operations") Cc: stable@dpdk.org Signed-off-by: Yajun Wu Acked-by: Matan Azrad --- drivers/common/mlx5/mlx5_devx_cmds.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/common/mlx5/mlx5_devx_cmds.c b/drivers/common/mlx5/mlx5_devx_cmds.c index 2e807a0829..7732613c69 100644 --- a/drivers/common/mlx5/mlx5_devx_cmds.c +++ b/drivers/common/mlx5/mlx5_devx_cmds.c @@ -2279,7 +2279,7 @@ mlx5_devx_cmd_modify_qp_state(struct mlx5_devx_obj *qp, uint32_t qp_st_mod_op, case MLX5_CMD_OP_RTR2RTS_QP: qpc = MLX5_ADDR_OF(rtr2rts_qp_in, &in, qpc); MLX5_SET(rtr2rts_qp_in, &in, qpn, qp->id); - MLX5_SET(qpc, qpc, primary_address_path.ack_timeout, 14); + MLX5_SET(qpc, qpc, primary_address_path.ack_timeout, 16); MLX5_SET(qpc, qpc, log_ack_req_freq, 0); MLX5_SET(qpc, qpc, retry_count, 7); MLX5_SET(qpc, qpc, rnr_retry, 7); -- 2.39.5