From 5919305351475dda04c0f6f28f388c89ffafcd2b Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Sat, 11 Jul 2020 22:32:06 +0200 Subject: [PATCH] net: fec: Set max MTU size to allow the MTU to be changed The FEC allocates 2K buffers, but looses some of it due to alignment. It can however support an MTU bigger than the default. This is particularly interesting when used in combination with Ethernet switches supporting DSA, which have extra headers. The DSA core will try to increase the MTU to support these extra headers. If the max size defaults to that of standard Ethernet we get a warning. By setting the max to what the driver actually supports, we avoid this warning. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 795693874e31..a93381284f08 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -3678,6 +3678,8 @@ fec_probe(struct platform_device *pdev) fec_enet_clk_enable(ndev, false); pinctrl_pm_select_sleep_state(&pdev->dev); + ndev->max_mtu = PKT_MAXBUF_SIZE - ETH_HLEN - ETH_FCS_LEN; + ret = register_netdev(ndev); if (ret) goto failed_register; -- 2.20.1