[dpdk-stable] [PATCH] net/mlx5: fix rss reta is reset when device is started

[Maxime Leroy <maxime.leroy@6wind.com>]

The following sequences was working fine on mlx5:
   rte_eth_dev_configure(portid, ...);

   for (queueid = 0; queueid < nb_txq; queueid++)
      rte_eth_tx_queue_setup(portid, queueid, ...);

   for (queueid = 0; queueid < nb_rxq; queueid++)
      rte_eth_rx_queue_setup(portid, queueid, ...);

  // use a custom reta configuration
  rte_eth_dev_rss_reta_update(portid, reta_conf, reta_size);
  rte_eth_dev_start(portid);

We were able to configure a custom reta before starting the port.

The commit "net/mlx5: support RSS on hairpin" breaks this logic by
moving the code initializing the RSS reta from rte_eth_dev_configure
into rte_eth_dev_start.

To fix the issue, the skip_default_rss_reta is always set to 1 in
rte_eth_dev_rss_reta to avoid reconfigure the rss reta when the device
is started.

Fixes: 63bd16292c3a ("net/mlx5: support RSS on hairpin")
Signed-off-by: Maxime Leroy <maxime.leroy@6wind.com>
---
 drivers/net/mlx5/mlx5_rss.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_rss.c b/drivers/net/mlx5/mlx5_rss.c
index 653b0691..6f75ece2 100644
--- a/drivers/net/mlx5/mlx5_rss.c
+++ b/drivers/net/mlx5/mlx5_rss.c
@@ -220,9 +220,11 @@ mlx5_dev_rss_reta_update(struct rte_eth_dev *dev,
 		MLX5_ASSERT(reta_conf[idx].reta[pos] < priv->rxqs_n);
 		(*priv->reta_idx)[i] = reta_conf[idx].reta[pos];
 	}
+
+	priv->skip_default_rss_reta = 1;
+
 	if (dev->data->dev_started) {
 		mlx5_dev_stop(dev);
-		priv->skip_default_rss_reta = 1;
 		return mlx5_dev_start(dev);
 	}
 	return 0;
-- 
2.27.0