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

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 <[email protected]>.

thanks,

greg k-h

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

From ada09af92e621ab500dd80a16d1d0299a18a1180 Mon Sep 17 00:00:00 2001
From: Vlad Buslov <[email protected]>
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.

index e3fc15ae7bb1..ac0f73074f7a 100644
@@ -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