Subject: [PATCH net-next v4 03/12] eth: mlx5: allow disabling queues when RSS contexts exist

From: Jakub Kicinski <[email-masked]>
Date: Thu, 8 Aug 2024 20:18:18 -0700

Since commit 24ac7e544081 ("ethtool: use the rss context XArray
in ring deactivation safety-check") core will prevent queues from
being disabled while being used by additional RSS contexts.
The safety check is no longer necessary, and core will do a more
accurate job of only rejecting changes which can actually break
things.

Reviewed-by: Gal Pressman <[email-masked]>
Reviewed-by: Joe Damato <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
---
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
CC: [email-masked]
---
 drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index 36845872ae94..0b941482db30 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -445,7 +445,6 @@ int mlx5e_ethtool_set_channels(struct mlx5e_priv *priv,
 	unsigned int count = ch->combined_count;
 	struct mlx5e_params new_params;
 	bool arfs_enabled;
-	int rss_cnt;
 	bool opened;
 	int err = 0;
 
@@ -499,17 +498,6 @@ int mlx5e_ethtool_set_channels(struct mlx5e_priv *priv,
 		goto out;
 	}
 
-	/* Don't allow changing the number of channels if non-default RSS contexts exist,
-	 * the kernel doesn't protect against set_channels operations that break them.
-	 */
-	rss_cnt = mlx5e_rx_res_rss_cnt(priv->rx_res) - 1;
-	if (rss_cnt) {
-		err = -EINVAL;
-		netdev_err(priv->netdev, "%s: Non-default RSS contexts exist (%d), cannot change the number of channels\n",
-			   __func__, rss_cnt);
-		goto out;
-	}
-
 	/* Don't allow changing the number of channels if MQPRIO mode channel offload is active,
 	 * because it defines a partition over the channels queues.
 	 */
-- 
2.46.0