ethernet: use core min/max MTU checking

et131x: min_mtu 64, max_mtu 9216

altera_tse: min_mtu 64, max_mtu 1500

amd8111e: min_mtu 60, max_mtu 9000

bnad: min_mtu 46, max_mtu 9000

macb: min_mtu 68, max_mtu 1500 or 10240 depending on hardware capability

xgmac: min_mtu 46, max_mtu 9000

cxgb2: min_mtu 68, max_mtu 9582 (pm3393) or 9600 (vsc7326)

enic: min_mtu 68, max_mtu 9000

gianfar: min_mtu 50, max_mu 9586

hns_enet: min_mtu 68, max_mtu 9578 (v1) or 9706 (v2)

ksz884x: min_mtu 60, max_mtu 1894

myri10ge: min_mtu 68, max_mtu 9000

natsemi: min_mtu 64, max_mtu 2024

nfp: min_mtu 68, max_mtu hardware-specific

forcedeth: min_mtu 64, max_mtu 1500 or 9100, depending on hardware

pch_gbe: min_mtu 46, max_mtu 10300

pasemi_mac: min_mtu 64, max_mtu 9000

qcaspi: min_mtu 46, max_mtu 1500
- remove qcaspi_netdev_change_mtu as it is now redundant

rocker: min_mtu 68, max_mtu 9000

sxgbe: min_mtu 68, max_mtu 9000

stmmac: min_mtu 46, max_mtu depends on hardware

tehuti: min_mtu 60, max_mtu 16384
- driver had no max mtu checking, but product docs say 16k jumbo packets
  are supported by the hardware

netcp: min_mtu 68, max_mtu 9486
- remove netcp_ndo_change_mtu as it is now redundant

via-velocity: min_mtu 64, max_mtu 9000

octeon: min_mtu 46, max_mtu 65370

CC: netdev@vger.kernel.org
CC: Mark Einon <mark.einon@gmail.com>
CC: Vince Bridgers <vbridger@opensource.altera.com>
CC: Rasesh Mody <rasesh.mody@qlogic.com>
CC: Nicolas Ferre <nicolas.ferre@atmel.com>
CC: Santosh Raspatur <santosh@chelsio.com>
CC: Hariprasad S <hariprasad@chelsio.com>
CC:  Christian Benvenuti <benve@cisco.com>
CC: Sujith Sankar <ssujith@cisco.com>
CC: Govindarajulu Varadarajan <_govind@gmx.com>
CC: Neel Patel <neepatel@cisco.com>
CC: Claudiu Manoil <claudiu.manoil@freescale.com>
CC: Yisen Zhuang <yisen.zhuang@huawei.com>
CC: Salil Mehta <salil.mehta@huawei.com>
CC: Hyong-Youb Kim <hykim@myri.com>
CC: Jakub Kicinski <jakub.kicinski@netronome.com>
CC: Olof Johansson <olof@lixom.net>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Byungho An <bh74.an@samsung.com>
CC: Girish K S <ks.giri@samsung.com>
CC: Vipul Pandya <vipul.pandya@samsung.com>
CC: Giuseppe Cavallaro <peppe.cavallaro@st.com>
CC: Alexandre Torgue <alexandre.torgue@st.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Wingman Kwok <w-kwok2@ti.com>
CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c

@@ -446,8 +446,7 @@ int hns_mac_set_mtu(struct hns_mac_cb *mac_cb, u32 new_mtu)
 	if (mac_cb->mac_type == HNAE_PORT_DEBUG)
 		max_frm = MAC_MAX_MTU_DBG;
 
-	if ((new_mtu < MAC_MIN_MTU) || (new_frm > max_frm) ||
-	    (new_frm > HNS_RCB_RING_MAX_BD_PER_PKT * buf_size))
+	if (new_frm > HNS_RCB_RING_MAX_BD_PER_PKT * buf_size)
 		return -EINVAL;
 
 	if (!drv->config_max_frame_length)

drivers/net/ethernet/hisilicon/hns/hns_enet.c

@@ -22,6 +22,7 @@
 
 #include "hnae.h"
 #include "hns_enet.h"
+#include "hns_dsaf_mac.h"
 
 #define NIC_MAX_Q_PER_VF 16
 #define HNS_NIC_TX_TIMEOUT (5 * HZ)
@@ -1405,10 +1406,6 @@ static int hns_nic_change_mtu(struct net_device *ndev, int new_mtu)
 	struct hnae_handle *h = priv->ae_handle;
 	int ret;
 
-	/* MTU < 68 is an error and causes problems on some kernels */
-	if (new_mtu < 68)
-		return -EINVAL;
-
 	if (!h->dev->ops->set_mtu)
 		return -ENOTSUPP;
 
@@ -1953,14 +1950,20 @@ static int hns_nic_dev_probe(struct platform_device *pdev)
 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_RXCSUM;
 	ndev->vlan_features |= NETIF_F_SG | NETIF_F_GSO | NETIF_F_GRO;
 
+	/* MTU range: 68 - 9578 (v1) or 9706 (v2) */
+	ndev->min_mtu = MAC_MIN_MTU;
 	switch (priv->enet_ver) {
 	case AE_VERSION_2:
 		ndev->features |= NETIF_F_TSO | NETIF_F_TSO6;
 		ndev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 			NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_GSO |
 			NETIF_F_GRO | NETIF_F_TSO | NETIF_F_TSO6;
+		ndev->max_mtu = MAC_MAX_MTU_V2 -
+				(ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
 		break;
 	default:
+		ndev->max_mtu = MAC_MAX_MTU -
+				(ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
 		break;
 	}