[PATCH v2] net/mlx5: fallback to verbs for Tx memory allocation if devx unsupported

[PATCH v2] net/mlx5: fallback to verbs for Tx memory allocation if devx unsupported

[banoth.saikumar]

From: Banoth Saikumar <banoth.saikumar@oracle.com>

Previously, the mlx5 PMD attempted to allocate consecutive Tx memory
using DevX without checking whether the NIC actually supported DevX.
This led to allocation failures on legacy or unsupported NICs.

This patch adds a fallback mechanism: if DevX is not available, the PMD
skips DevX-based allocation and allows the verbs path to handle memory
allocation and registration. This improves compatibility with older
NICs and ensures Tx queue setup proceeds correctly.

Fixes: bbfab2eb2528 ("net/mlx5: allocate and release unique
resources for Tx queues")
Cc: stable@dpdk.org

Signed-off-by: Banoth Saikumar <banoth.saikumar@oracle.com>
---
v2:
- Use mlx5_devx_obj_ops_en() instead of checking config.devx directly.

 drivers/net/mlx5/mlx5_trigger.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
index 6c6f228afd..721fa5e2c8 100644
--- a/drivers/net/mlx5/mlx5_trigger.c
+++ b/drivers/net/mlx5/mlx5_trigger.c
@@ -1161,7 +1161,7 @@ static int mlx5_dev_allocate_consec_tx_mem(struct rte_eth_dev *dev)
 	void *umem_buf = NULL;
 
 	/* Legacy per queue allocation, do nothing here. */
-	if (priv->sh->config.txq_mem_algn == 0)
+	if (priv->sh->config.txq_mem_algn == 0 || !mlx5_devx_obj_ops_en(priv->sh))
 		return 0;
 	alignment = (size_t)1 << priv->sh->config.txq_mem_algn;
 	total_size = priv->consec_tx_mem.sq_total_size + priv->consec_tx_mem.cq_total_size;
-- 
2.47.3