net: ethernet: mtk_eth_soc: fix MTU warnings

[ 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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index be390c7e43b2faf39c99174eb02d63f064209f08..d01b3a1b40f4aa9e4d72c82145dd36b94d81c677 100644 (file)
--- 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: