net: ethernet: mtk_eth_soc: fix MTU warnings

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: b202c04f8d0d ("net: dsa: configure the MTU for switch ports")
Fixes: b0813ca8f4d8 ("net: dsa: don't fail to probe if we couldn't set the MTU")
Fixes: 2cfe5260cdd8 ("net: report invalid mtu value via netlink extack")
Signed-off-by: Landen Chao <landen.chao@mediatek.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 85735d32ecb0d8d0989a46555df6c2f6079887a2..a1c45b39a2301a38f8e3d8614c76e4637f9d36d4 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2891,6 +2891,8 @@ 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: