e1000e: Support RXFCS feature flag.
This enables enabling/disabling reception of the Ethernet
FCS. This can be useful when sniffing packets.
For e1000e, enabling RXFCS can change the default
behaviour for how the NIC handles CRC. Disabling RXFCS
will take the NIC back to defaults, which can be configured
as part of the module options.
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/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c079b9b..30c8c15 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -933,8 +933,16 @@
}
/* adjust length to remove Ethernet CRC */
- if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
- length -= 4;
+ if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+ /* If configured to store CRC, don't subtract FCS,
+ * but keep the FCS bytes out of the total_rx_bytes
+ * counter
+ */
+ if (netdev->features & NETIF_F_RXFCS)
+ total_rx_bytes -= 4;
+ else
+ length -= 4;
+ }
total_rx_bytes += length;
total_rx_packets++;
@@ -1301,8 +1309,10 @@
DMA_FROM_DEVICE);
/* remove the CRC */
- if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
- l1 -= 4;
+ if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+ if (!(netdev->features & NETIF_F_RXFCS))
+ l1 -= 4;
+ }
skb_put(skb, l1);
goto copydone;
@@ -1328,8 +1338,10 @@
/* strip the ethernet crc, problem is we're using pages now so
* this whole operation can get a little cpu intensive
*/
- if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
- pskb_trim(skb, skb->len - 4);
+ if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+ if (!(netdev->features & NETIF_F_RXFCS))
+ pskb_trim(skb, skb->len - 4);
+ }
copydone:
total_rx_bytes += skb->len;
@@ -5982,7 +5994,7 @@
adapter->flags |= FLAG_TSO_FORCE;
if (!(changed & (NETIF_F_HW_VLAN_RX | NETIF_F_HW_VLAN_TX |
- NETIF_F_RXCSUM | NETIF_F_RXHASH)))
+ NETIF_F_RXCSUM | NETIF_F_RXHASH | NETIF_F_RXFCS)))
return 0;
/*
@@ -5996,6 +6008,20 @@
return -EINVAL;
}
+ if (changed & NETIF_F_RXFCS) {
+ if (features & NETIF_F_RXFCS) {
+ adapter->flags2 &= ~FLAG2_CRC_STRIPPING;
+ } else {
+ /* We need to take it back to defaults, which might mean
+ * stripping is still disabled at the adapter level.
+ */
+ if (adapter->flags2 & FLAG2_DFLT_CRC_STRIPPING)
+ adapter->flags2 |= FLAG2_CRC_STRIPPING;
+ else
+ adapter->flags2 &= ~FLAG2_CRC_STRIPPING;
+ }
+ }
+
netdev->features = features;
if (netif_running(netdev))
@@ -6194,6 +6220,7 @@
/* Set user-changeable features (subset of all device features) */
netdev->hw_features = netdev->features;
+ netdev->hw_features |= NETIF_F_RXFCS;
if (adapter->flags & FLAG_HAS_HW_VLAN_FILTER)
netdev->features |= NETIF_F_HW_VLAN_FILTER;