FAILED: patch "[PATCH] net/mlx5e: Don't match double-vlan packets if cvlan is not" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ada09af92e621ab500dd80a16d1d0299a18a1180 Mon Sep 17 00:00:00 2001
From: Vlad Buslov <vladbu@nvidia.com>
Date: Mon, 28 Mar 2022 15:54:52 +0300
Subject: [PATCH] net/mlx5e: Don't match double-vlan packets if cvlan is not
 set

Currently, match VLAN rule also matches packets that have multiple VLAN
headers. This behavior is similar to buggy flower classifier behavior that
has recently been fixed. Fix the issue by matching on
outer_second_cvlan_tag with value 0 which will cause the HW to verify the
packet doesn't contain second vlan header.

Fixes: 699e96ddf47f ("net/mlx5e: Support offloading tc double vlan headers match")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index e3fc15ae7bb1..ac0f73074f7a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2459,6 +2459,17 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 				 match.key->vlan_priority);
 
 			*match_level = MLX5_MATCH_L2;
+
+			if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_CVLAN) &&
+			    match.mask->vlan_eth_type &&
+			    MLX5_CAP_FLOWTABLE_TYPE(priv->mdev,
+						    ft_field_support.outer_second_vid,
+						    fs_type)) {
+				MLX5_SET(fte_match_set_misc, misc_c,
+					 outer_second_cvlan_tag, 1);
+				spec->match_criteria_enable |=
+					MLX5_MATCH_MISC_PARAMETERS;
+			}
 		}
 	} else if (*match_level != MLX5_MATCH_NONE) {
 		/* cvlan_tag enabled in match criteria and