Subject: [PATCH 04/24] net: ethernet: octeon_mgmt: Account for second possible VLAN header

From: Alexander Sverdlin <[email-masked]>
Date: Fri, 8 Nov 2019 10:00:44 +0000

[ Upstream commit e4dd5608033efe7b6030cde359bfdbaeb73bc22d ]

Octeon's input ring-buffer entry has 14 bits-wide size field, so to account
for second possible VLAN header max_mtu must be further reduced.

Fixes: 109cc16526c6d ("ethernet/cavium: use core min/max MTU checking")
Signed-off-by: Alexander Sverdlin <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/cavium/octeon/octeon_mgmt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c b/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
index 0e5de88fd6e8..cdd7e5da4a74 100644
--- a/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
+++ b/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
@@ -1499,7 +1499,7 @@ static int octeon_mgmt_probe(struct platform_device *pdev)
 	netdev->ethtool_ops = &octeon_mgmt_ethtool_ops;
 
 	netdev->min_mtu = 64 - OCTEON_MGMT_RX_HEADROOM;
-	netdev->max_mtu = 16383 - OCTEON_MGMT_RX_HEADROOM;
+	netdev->max_mtu = 16383 - OCTEON_MGMT_RX_HEADROOM - VLAN_HLEN;
 
 	mac = of_get_mac_address(pdev->dev.of_node);
 
-- 
2.20.1