From e90e9226bea32e2f7eed3d35b4223f67ee3067e2 Mon Sep 17 00:00:00 2001
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sun, 22 Mar 2020 13:58:50 -0700
Subject: [PATCH] net: dsa: Fix duplicate frames flooded by learning

[ Upstream commit 0e62f543bed03a64495bd2651d4fe1aa4bcb7fe5 ]

When both the switch and the bridge are learning about new addresses,
switch ports attached to the bridge would see duplicate ARP frames
because both entities would attempt to send them.

Fixes: 5037d532b83d ("net: dsa: add Broadcom tag RX/TX handler")
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/dsa/tag_brcm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index 2b06bb91318b..2709bddef7d5 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c
@@ -141,6 +141,8 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
 	/* Remove Broadcom tag and update checksum */
 	skb_pull_rcsum(skb, BRCM_TAG_LEN);
 
+	skb->offload_fwd_mark = 1;
+
 	return skb;
 }