net: use core MTU range checking in USB NIC drivers

usbnet:
- Remove stale new_mtu <= 0 check in usbnet.c
- Set min_mtu = 0, max_mtu = 65535 (sub-drivers must set their own
  max_mtu and/or min_mtu as needed)

r8152:
- Set appropriate max_mtu for different variants (1500 or 9194)

lan78xx:
- Set max_mtu = 9000

asix_driver:
- max_mtu = 16384 for ax88178 variant

ax88179:
- max_mtu = 4088

cdc_ncm:
- max_mtu from hardware

cdc-phonet:
- min_mtu = 6, max_mtu = 65541

sierra_net:
- max_mtu = 1500, call usbnet_change_mtu directly
- sierra_net_change_mtu checked for MTU > 1500, then called
  usbnet_change_mtu, but if we set max_mtu to let the network core handle
  the range check, then we can simply call usbnet_change_mtu directly

smsc75xx:
- max_mtu = 9000

CC: netdev@vger.kernel.org
CC: Woojung Huh <woojung.huh@microchip.com>
CC: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
CC: Hayes Wang <hayeswang@realtek.com>
CC: Oliver Neukum <oneukum@suse.com>
CC: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 11 deletions

diff --git a/drivers/net/usb/sierra_net.c b/drivers/net/usb/sierra_net.c
index a251588762ec..12071f1582df 100644
--- a/drivers/net/usb/sierra_net.c
+++ b/drivers/net/usb/sierra_net.c
@@ -165,7 +165,6 @@ struct lsi_umts {
 
 /* Forward definitions */
 static void sierra_sync_timer(unsigned long syncdata);
-static int sierra_net_change_mtu(struct net_device *net, int new_mtu);
 
 /* Our own net device operations structure */
 static const struct net_device_ops sierra_net_device_ops = {
@@ -173,7 +172,7 @@ static const struct net_device_ops sierra_net_device_ops = {
 	.ndo_stop               = usbnet_stop,
 	.ndo_start_xmit         = usbnet_start_xmit,
 	.ndo_tx_timeout         = usbnet_tx_timeout,
-	.ndo_change_mtu         = sierra_net_change_mtu,
+	.ndo_change_mtu         = usbnet_change_mtu,
 	.ndo_set_mac_address    = eth_mac_addr,
 	.ndo_validate_addr      = eth_validate_addr,
 };
@@ -622,15 +621,6 @@ static const struct ethtool_ops sierra_net_ethtool_ops = {
 	.nway_reset = usbnet_nway_reset,
 };
 
-/* MTU can not be more than 1500 bytes, enforce it. */
-static int sierra_net_change_mtu(struct net_device *net, int new_mtu)
-{
-	if (new_mtu > SIERRA_NET_MAX_SUPPORTED_MTU)
-		return -EINVAL;
-
-	return usbnet_change_mtu(net, new_mtu);
-}
-
 static int sierra_net_get_fw_attr(struct usbnet *dev, u16 *datap)
 {
 	int result = 0;
@@ -720,6 +710,7 @@ static int sierra_net_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	dev->net->hard_header_len += SIERRA_NET_HIP_EXT_HDR_LEN;
 	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
+	dev->net->max_mtu = SIERRA_NET_MAX_SUPPORTED_MTU;
 
 	/* Set up the netdev */
 	dev->net->flags |= IFF_NOARP;