Subject: [PATCH 05/18] net: ethernet: mtk_eth_soc: fix MTU warnings

From: Landen Chao <[email-masked]>
Date: Wed, 29 Jul 2020 10:15:17 +0200

[ Upstream commit 555a893303872e044fb86f0a5834ce78d41ad2e2 ]

in recent kernel versions there are warnings about incorrect MTU size
like these:

eth0: mtu greater than device maximum
mtk_soc_eth 1b100000.ethernet eth0: error -22 setting MTU to include DSA overhead

Fixes: bfcb813203e6 ("net: dsa: configure the MTU for switch ports")
Fixes: 72579e14a1d3 ("net: dsa: don't fail to probe if we couldn't set the MTU")
Fixes: 7a4c53bee332 ("net: report invalid mtu value via netlink extack")
Signed-off-by: Landen Chao <[email-masked]>
Signed-off-by: Frank Wunderlich <[email-masked]>
Reviewed-by: Andrew Lunn <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index be390c7e43b2..d01b3a1b40f4 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2878,6 +2878,8 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	eth->netdev[id]->irq = eth->irq[0];
 	eth->netdev[id]->dev.of_node = np;
 
+	eth->netdev[id]->max_mtu = MTK_MAX_RX_LENGTH - MTK_RX_ETH_HLEN;
+
 	return 0;
 
 free_netdev:
-- 
2.26.2