net: systemport: Fix reception of BPDUs

BugLink: https://bugs.launchpad.net/bugs/1837952
[ 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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index c9fa6829844aa748f96d358a7306fa1279d3e13d..68846cd230d87c174f4706115254d6841b49c83b 100644 (file)
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -134,6 +134,10 @@ static int 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