--- zzzz-none-000/linux-4.9.279/drivers/net/ethernet/broadcom/sb1250-mac.c	2021-08-08 06:38:54.000000000 +0000
+++ puma7-atom-6591-750/linux-4.9.279/drivers/net/ethernet/broadcom/sb1250-mac.c	2023-02-08 11:43:42.000000000 +0000
@@ -2147,15 +2147,6 @@
 	}
 }
 
-static int sb1250_change_mtu(struct net_device *_dev, int new_mtu)
-{
-	if (new_mtu >  ENET_PACKET_SIZE)
-		return -EINVAL;
-	_dev->mtu = new_mtu;
-	pr_info("changing the mtu to %d\n", new_mtu);
-	return 0;
-}
-
 static const struct net_device_ops sbmac_netdev_ops = {
 	.ndo_open		= sbmac_open,
 	.ndo_stop		= sbmac_close,
@@ -2163,7 +2154,6 @@
 	.ndo_set_rx_mode	= sbmac_set_rx_mode,
 	.ndo_tx_timeout		= sbmac_tx_timeout,
 	.ndo_do_ioctl		= sbmac_mii_ioctl,
-	.ndo_change_mtu		= sb1250_change_mtu,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_set_mac_address	= eth_mac_addr,
 #ifdef CONFIG_NET_POLL_CONTROLLER
@@ -2229,6 +2219,8 @@
 
 	dev->netdev_ops = &sbmac_netdev_ops;
 	dev->watchdog_timeo = TX_TIMEOUT;
+	dev->max_mtu = 0;
+	dev->max_mtu = ENET_PACKET_SIZE;
 
 	netif_napi_add(dev, &sc->napi, sbmac_poll, 16);