From: Landen Chao <landen.chao@xxxxxxxxxxxx> [ 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 <landen.chao@xxxxxxxxxxxx> Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 ++ 1 file changed, 2 insertions(+) --- 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 *e 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: