ethernet/atheros: use core min/max MTU checking

atl2: min_mtu 40, max_mtu 1504

- Remove a few redundant defines that already have equivalents in
  if_ether.h.

atl1: min_mtu 42, max_mtu 10218

atl1e: min_mtu 42, max_mtu 8170

atl1c: min_mtu 42, max_mtu 6122/1500

- GbE hardware gets a max_mtu of 6122, slower hardware gets 1500.

alx: min_mtu 34, max_mtu 9256

- Not so sure that minimum MTU number is really what was intended, but
  that's what the math actually makes it out to be, due to max_frame
  manipulations and comparison in alx_change_mtu, rather than just
  comparing new_mtu. (I think 68 was the intended min_mtu value).

CC: netdev@vger.kernel.org
CC: Jay Cliburn <jcliburn@gmail.com>
CC: Chris Snook <chris.snook@gmail.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 13 insertions, 21 deletions

diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
index 529bca718334..9aede18aa70f 100644
--- a/drivers/net/ethernet/atheros/atlx/atl1.c
+++ b/drivers/net/ethernet/atheros/atlx/atl1.c
@@ -2701,23 +2701,15 @@ static void atl1_reset_dev_task(struct work_struct *work)
 static int atl1_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct atl1_adapter *adapter = netdev_priv(netdev);
-	int old_mtu = netdev->mtu;
 	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
 
-	if ((max_frame < ETH_ZLEN + ETH_FCS_LEN) ||
-	    (max_frame > MAX_JUMBO_FRAME_SIZE)) {
-		if (netif_msg_link(adapter))
-			dev_warn(&adapter->pdev->dev, "invalid MTU setting\n");
-		return -EINVAL;
-	}
-
 	adapter->hw.max_frame_size = max_frame;
 	adapter->hw.tx_jumbo_task_th = (max_frame + 7) >> 3;
 	adapter->rx_buffer_len = (max_frame + 7) & ~7;
 	adapter->hw.rx_jumbo_th = adapter->rx_buffer_len / 8;
 
 	netdev->mtu = new_mtu;
-	if ((old_mtu != new_mtu) && netif_running(netdev)) {
+	if (netif_running(netdev)) {
 		atl1_down(adapter);
 		atl1_up(adapter);
 	}
@@ -3031,6 +3023,11 @@ static int atl1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	/* is this valid? see atl1_setup_mac_ctrl() */
 	netdev->features |= NETIF_F_RXCSUM;
 
+	/* MTU range: 42 - 10218 */
+	netdev->min_mtu = ETH_ZLEN - (ETH_HLEN + VLAN_HLEN);
+	netdev->max_mtu = MAX_JUMBO_FRAME_SIZE -
+			  (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
+
 	/*
 	 * patch for some L1 of old version,
 	 * the final version of L1 may not need these
diff --git a/drivers/net/ethernet/atheros/atlx/atl2.c b/drivers/net/ethernet/atheros/atlx/atl2.c
index 2ff465848b65..6911394115b2 100644
--- a/drivers/net/ethernet/atheros/atlx/atl2.c
+++ b/drivers/net/ethernet/atheros/atlx/atl2.c
@@ -253,7 +253,7 @@ static int atl2_configure(struct atl2_adapter *adapter)
 
 	/* set MTU */
 	ATL2_WRITE_REG(hw, REG_MTU, adapter->netdev->mtu +
-		ENET_HEADER_SIZE + VLAN_SIZE + ETHERNET_FCS_SIZE);
+		ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
 
 	/* 1590 */
 	ATL2_WRITE_REG(hw, REG_TX_CUT_THRESH, 0x177);
@@ -925,15 +925,11 @@ static int atl2_change_mtu(struct net_device *netdev, int new_mtu)
 	struct atl2_adapter *adapter = netdev_priv(netdev);
 	struct atl2_hw *hw = &adapter->hw;
 
-	if ((new_mtu < 40) || (new_mtu > (ETH_DATA_LEN + VLAN_SIZE)))
-		return -EINVAL;
-
 	/* set MTU */
-	if (hw->max_frame_size != new_mtu) {
-		netdev->mtu = new_mtu;
-		ATL2_WRITE_REG(hw, REG_MTU, new_mtu + ENET_HEADER_SIZE +
-			VLAN_SIZE + ETHERNET_FCS_SIZE);
-	}
+	netdev->mtu = new_mtu;
+	hw->max_frame_size = new_mtu;
+	ATL2_WRITE_REG(hw, REG_MTU, new_mtu + ETH_HLEN +
+		       VLAN_HLEN + ETH_FCS_LEN);
 
 	return 0;
 }
@@ -1398,6 +1394,8 @@ static int atl2_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	netdev->netdev_ops = &atl2_netdev_ops;
 	netdev->ethtool_ops = &atl2_ethtool_ops;
 	netdev->watchdog_timeo = 5 * HZ;
+	netdev->min_mtu = 40;
+	netdev->max_mtu = ETH_DATA_LEN + VLAN_HLEN;
 	strncpy(netdev->name, pci_name(pdev), sizeof(netdev->name) - 1);
 
 	netdev->mem_start = mmio_start;
diff --git a/drivers/net/ethernet/atheros/atlx/atl2.h b/drivers/net/ethernet/atheros/atlx/atl2.h
index 2f27d4c4c3ad..c64a6bdfa7ae 100644
--- a/drivers/net/ethernet/atheros/atlx/atl2.h
+++ b/drivers/net/ethernet/atheros/atlx/atl2.h
@@ -228,12 +228,9 @@ static void atl2_force_ps(struct atl2_hw *hw);
 #define AUTONEG_ADVERTISE_SPEED_DEFAULT	0x000F	/* Everything */
 
 /* The size (in bytes) of a ethernet packet */
-#define ENET_HEADER_SIZE		14
 #define MAXIMUM_ETHERNET_FRAME_SIZE	1518	/* with FCS */
 #define MINIMUM_ETHERNET_FRAME_SIZE	64	/* with FCS */
-#define ETHERNET_FCS_SIZE		4
 #define MAX_JUMBO_FRAME_SIZE		0x2000
-#define VLAN_SIZE                                               4
 
 struct tx_pkt_header {
 	unsigned pkt_size:11;