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>

1 files changed, 26 insertions, 15 deletions

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index a3200ea6d765..773d3b7d8dd5 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -519,6 +519,26 @@ static int atl1c_set_features(struct net_device *netdev,
 	return 0;
 }
 
+static void atl1c_set_max_mtu(struct net_device *netdev)
+{
+	struct atl1c_adapter *adapter = netdev_priv(netdev);
+	struct atl1c_hw *hw = &adapter->hw;
+
+	switch (hw->nic_type) {
+	/* These (GbE) devices support jumbo packets, max_mtu 6122 */
+	case athr_l1c:
+	case athr_l1d:
+	case athr_l1d_2:
+		netdev->max_mtu = MAX_JUMBO_FRAME_SIZE -
+				  (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
+		break;
+	/* The 10/100 devices don't support jumbo packets, max_mtu 1500 */
+	default:
+		netdev->max_mtu = ETH_DATA_LEN;
+		break;
+	}
+}
+
 /**
  * atl1c_change_mtu - Change the Maximum Transfer Unit
  * @netdev: network interface device structure
@@ -529,22 +549,9 @@ static int atl1c_set_features(struct net_device *netdev,
 static int atl1c_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct atl1c_adapter *adapter = netdev_priv(netdev);
-	struct atl1c_hw *hw = &adapter->hw;
-	int old_mtu   = netdev->mtu;
-	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
-
-	/* Fast Ethernet controller doesn't support jumbo packet */
-	if (((hw->nic_type == athr_l2c ||
-	      hw->nic_type == athr_l2c_b ||
-	      hw->nic_type == athr_l2c_b2) && new_mtu > ETH_DATA_LEN) ||
-	      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;
-	}
+
 	/* set MTU */
-	if (old_mtu != new_mtu && netif_running(netdev)) {
+	if (netif_running(netdev)) {
 		while (test_and_set_bit(__AT_RESETTING, &adapter->flags))
 			msleep(1);
 		netdev->mtu = new_mtu;
@@ -2511,6 +2518,7 @@ static int atl1c_init_netdev(struct net_device *netdev, struct pci_dev *pdev)
 
 	netdev->netdev_ops = &atl1c_netdev_ops;
 	netdev->watchdog_timeo = AT_TX_WATCHDOG;
+	netdev->min_mtu = ETH_ZLEN - (ETH_HLEN + VLAN_HLEN);
 	atl1c_set_ethtool_ops(netdev);
 
 	/* TODO: add when ready */
@@ -2613,6 +2621,9 @@ static int atl1c_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		dev_err(&pdev->dev, "net device private data init failed\n");
 		goto err_sw_init;
 	}
+	/* set max MTU */
+	atl1c_set_max_mtu(netdev);
+
 	atl1c_reset_pcie(&adapter->hw, ATL1C_PCIE_L0S_L1_DISABLE);
 
 	/* Init GPHY as early as possible due to power saving issue  */