From: Alex Vesker <valex@mellanox.com>
Date: Thu, 31 Oct 2019 15:24:59 +0200
Subject: net/mlx5: DR, Skip rehash for tables with byte mask zero
Patch-mainline: v5.4
Git-commit: 83e79489135bdf13590ad09f3341f9ef509c2cf9
References: jsc#SLE-8464

The byte mask fields affect on the hash index distribution,
when the byte mask is zero, the hash calculation will always
be equal to the same index.

To avoid unneeded rehash of hash tables mark the table to skip
rehash.

This is needed by the next patch which will limit table rehash
to reduce memory consumption.

Fixes: 41d07074154c ("net/mlx5: DR, Expose steering rule functionality")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste.c
@@ -671,7 +671,7 @@ static void dr_ste_set_ctrl(struct mlx5d
 
 	htbl->ctrl.may_grow = true;
 
-	if (htbl->chunk_size == DR_CHUNK_SIZE_MAX - 1)
+	if (htbl->chunk_size == DR_CHUNK_SIZE_MAX - 1 || !htbl->byte_mask)
 		htbl->ctrl.may_grow = false;
 
 	/* Threshold is 50%, one is added to table of size 1 */