net/mlx5: fix Tx when inlining is impossible

When txq_inline_max is too large and an mbuf is multi-segment
it may be impossible to inline data and build a valid WQE,
because WQE length would be larger then HW can represent.
It is impossible to detect misconfiguration at startup,
because the condition depends on the mbuf composition.
The check on the data path to prevent the error
treated the length limit as expressed in 64B units,
while the calculated length and limit are in 16B units.
Fix the condition to avoid subsequent TxQ failure and recovery.

Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
Cc: stable@dpdk.org
Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

diff --git a/drivers/net/mlx5/mlx5_tx.h b/drivers/net/mlx5/mlx5_tx.h
index 89dac0c65a748acca19c99140e73a69b400c3af8..dfa04612ff2ecb8d94d73d651e0cf6e48180cc59 100644 (file)
--- a/drivers/net/mlx5/mlx5_tx.h
+++ b/drivers/net/mlx5/mlx5_tx.h
@@ -2070,7 +2070,7 @@ do_build:
        if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
                return MLX5_TXCMP_CODE_EXIT;
        /* Check for maximal WQE size. */
-       if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
+       if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ds))
                return MLX5_TXCMP_CODE_ERROR;
 #ifdef MLX5_PMD_SOFT_COUNTERS
        /* Update sent data bytes/packets counters. */