[dpdk-dev] [PATCH 05/11] net/mlx5: fix DevX scattered Rx queue size

[Matan Azrad <matan@mellanox.com>]

The WQ size configuration via DevX didn't take into acount the maximum
number of segments per packet what wrongly caused to configure bigger
WQE size than the size expected by the PMD in other places.

The scatter mode stride size should be the size of segment multiplied
by the number of maximum segments per packet.
The number of WQEs per WQ should be the number of descriptors divided by
the number of the maximum segments per packet.

Fix the size calculations to the above rule.

Fixes: dc9ceff73c99 ("net/mlx5: create advanced RxQ via DevX")

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index d10c5c1..c95627e 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -1090,7 +1090,7 @@
 	struct mlx5_rxq_ctrl *rxq_ctrl =
 		container_of(rxq_data, struct mlx5_rxq_ctrl, rxq);
 	struct mlx5_devx_create_rq_attr rq_attr;
-	uint32_t wqe_n = 1 << rxq_data->elts_n;
+	uint32_t wqe_n = 1 << (rxq_data->elts_n - rxq_data->sges_n);
 	uint32_t wq_size = 0;
 	uint32_t wqe_size = 0;
 	uint32_t log_wqe_size = 0;
@@ -1118,17 +1118,11 @@
 				MLX5_MIN_SINGLE_STRIDE_LOG_NUM_BYTES;
 		wqe_size = sizeof(struct mlx5_wqe_mprq);
 	} else {
-		int max_sge = 0;
-		int num_scatter = 0;
-
-		rq_attr.wq_attr.wq_type = MLX5_WQ_TYPE_CYCLIC;
-		max_sge = 1 << rxq_data->sges_n;
-		num_scatter = RTE_MAX(max_sge, 1);
-		wqe_size = sizeof(struct mlx5_wqe_data_seg) * num_scatter;
+		wqe_size = sizeof(struct mlx5_wqe_data_seg);
 	}
-	log_wqe_size = log2above(wqe_size);
+	log_wqe_size = log2above(wqe_size) + rxq_data->sges_n;
 	rq_attr.wq_attr.log_wq_stride = log_wqe_size;
-	rq_attr.wq_attr.log_wq_sz = rxq_data->elts_n;
+	rq_attr.wq_attr.log_wq_sz = rxq_data->elts_n - rxq_data->sges_n;
 	/* Calculate and allocate WQ memory space. */
 	wqe_size = 1 << log_wqe_size; /* round up power of two.*/
 	wq_size = wqe_n * wqe_size;
-- 
1.8.3.1