net/mlx5: fix redundant flow after RSS expansion

[ upstream commit c1d397a ]

When RSS expand, if there is no expansion happened but completion
happened because user only input next protocol field instead of item
i.e, ether type == 0x8100 instead of VLAN, an extra flow is created with
missing item in order to filter traffic strictly.

However, after [1] and [2] the rte_flow_item_eth itself is enough to
filter out VLAN traffic, the VLAN item is not needed.

[1]: commit 09315fc ("ethdev: add VLAN attributes to ethernet and VLAN items")
[2]: commit 86b59a1 ("net/mlx5: support VLAN matching fields")

This redundant flow will cause failure in some scenarios on group 0 due
to they are the same FTE.

Fixes: fc2dd8d ("ethdev: fix expand RSS flows")

Signed-off-by: Xiaoyu Min <jackmin@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>

drivers/net/mlx5/mlx5_flow.c

@@ -385,22 +385,6 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 		}
 		node = *next_node ? &graph[*next_node] : NULL;
 	};
-	/* no expanded flows but we have missed item, create one rule for it */
-	if (buf->entries == 1 && missed != 0) {
-		elt = 2;
-		lsize += elt * sizeof(*item) + user_pattern_size;
-		if (lsize <= size) {
-			buf->entry[buf->entries].priority = 1;
-			buf->entry[buf->entries].pattern = addr;
-			buf->entries++;
-			flow_items[0].type = missed_item.type;
-			flow_items[1].type = RTE_FLOW_ITEM_TYPE_END;
-			rte_memcpy(addr, buf->entry[0].pattern,
-				   user_pattern_size);
-			addr = (void *)(((uintptr_t)addr) + user_pattern_size);
-			rte_memcpy(addr, flow_items, elt * sizeof(*item));
-		}
-	}
 	return lsize;
 }