atl1: fix frame length bug

The driver sets up the hardware to accept a frame with max length
equal to MTU + Ethernet header + FCS + VLAN tag, but we neglect to
add the VLAN tag size to the ingress buffer. When a VLAN-tagged
frame arrives, the hardware passes it, but bad things happen
because the buffer is too small. This patch fixes that.

Thanks to David Harris for reporting the bug and testing the fix.

Tested-by: David Harris <[e-mail]>
Signed-off-by: Jay Cliburn <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/atl1/atl1_main.c

···
 	struct atl1_hw *hw = &adapter->hw;
 	struct net_device *netdev = adapter->netdev;
 
-	hw->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN;
+	hw->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
 	hw->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
 
 	adapter->wol = 0;
···
 {
 	struct atl1_adapter *adapter = netdev_priv(netdev);
 	int old_mtu = netdev->mtu;
-	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+	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)) {
···
 	/* set Interrupt Clear Timer */
 	iowrite16(adapter->ict, hw->hw_addr + REG_CMBDISDMA_TIMER);
 
-	/* set MTU, 4 : VLAN */
-	iowrite32(hw->max_frame_size + 4, hw->hw_addr + REG_MTU);
+	/* set max frame size hw will accept */
+	iowrite32(hw->max_frame_size, hw->hw_addr + REG_MTU);
 
 	/* jumbo size & rrd retirement timer */
 	value = (((u32) hw->rx_jumbo_th & RXQ_JMBOSZ_TH_MASK)