e1000: Support sending custom Ethernet CRC.

Good for testing the RX logic for bad CRC handling.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index e72dc81..bd1d28f 100644 (file)
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -1067,6 +1067,8 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
           (hw->mac_type != e1000_82547))
                netdev->hw_features |= NETIF_F_TSO;
 
+       netdev->priv_flags |= IFF_SUPP_NOFCS;
+
        netdev->features |= netdev->hw_features;
        netdev->hw_features |= NETIF_F_RXCSUM;
 
@@ -2692,6 +2694,7 @@ set_itr_now:
 #define E1000_TX_FLAGS_VLAN            0x00000002
 #define E1000_TX_FLAGS_TSO             0x00000004
 #define E1000_TX_FLAGS_IPV4            0x00000008
+#define E1000_TX_FLAGS_NO_FCS          0x00000010
 #define E1000_TX_FLAGS_VLAN_MASK       0xffff0000
 #define E1000_TX_FLAGS_VLAN_SHIFT      16
 
@@ -2993,6 +2996,9 @@ static void e1000_tx_queue(struct e1000_adapter *adapter,
                txd_upper |= (tx_flags & E1000_TX_FLAGS_VLAN_MASK);
        }
 
+       if (unlikely(tx_flags & E1000_TX_FLAGS_NO_FCS))
+               txd_lower &= ~(E1000_TXD_CMD_IFCS);
+
        i = tx_ring->next_to_use;
 
        while (count--) {
@@ -3007,6 +3013,10 @@ static void e1000_tx_queue(struct e1000_adapter *adapter,
 
        tx_desc->lower.data |= cpu_to_le32(adapter->txd_cmd);
 
+       /* txd_cmd re-enables FCS, so we'll re-disable it here as desired. */
+       if (unlikely(tx_flags & E1000_TX_FLAGS_NO_FCS))
+               tx_desc->lower.data &= ~(cpu_to_le32(E1000_TXD_CMD_IFCS));
+
        /* Force memory writes to complete before letting h/w
         * know there are new descriptors to fetch.  (Only
         * applicable for weak-ordered memory model archs,
@@ -3222,6 +3232,9 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
        if (likely(skb->protocol == htons(ETH_P_IP)))
                tx_flags |= E1000_TX_FLAGS_IPV4;
 
+       if (unlikely(skb->no_fcs))
+               tx_flags |= E1000_TX_FLAGS_NO_FCS;
+
        count = e1000_tx_map(adapter, tx_ring, skb, first, max_per_txd,
                             nr_frags, mss);