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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.20 15/60] net: systemport: Fix reception of BPDUs
Date:   Wed, 13 Mar 2019 15:09:36 -0400
Message-Id: <20190313191021.158171-15-sashal@kernel.org>
In-Reply-To: <20190313191021.158171-1-sashal@kernel.org>
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From: Florian Fainelli <f.fainelli@gmail.com>

[ Upstream commit a40061ea2e39494104602b3048751341bda374a1 ]

SYSTEMPORT has its RXCHK parser block that attempts to validate the
packet structures, unfortunately setting the L2 header check bit will
cause Bridge PDUs (BPDUs) to be incorrectly rejected because they look
like LLC/SNAP packets with a non-IPv4 or non-IPv6 Ethernet Type.

Fixes: 4e8aedfe78c7 ("net: systemport: Turn on offloads by default")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index baa109040b40..f389bfe41eff 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -134,6 +134,10 @@ static void bcm_sysport_set_rx_csum(struct net_device *dev,
 
 	priv->rx_chk_en = !!(wanted & NETIF_F_RXCSUM);
 	reg = rxchk_readl(priv, RXCHK_CONTROL);
+	/* Clear L2 header checks, which would prevent BPDUs
+	 * from being received.
+	 */
+	reg &= ~RXCHK_L2_HDR_DIS;
 	if (priv->rx_chk_en)
 		reg |= RXCHK_EN;
 	else
-- 
2.19.1