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>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index e72dc8175955..bd1d28f4cc9a 100644
--- 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);