The Gianfar Ethernet Driver
  
  Author: Andy Fleming <afleming@freescale.com>
  Updated: 2005-07-28
  
  
  CHECKSUM OFFLOADING
  
  The eTSEC controller (first included in parts from late 2005 like
  the 8548) has the ability to perform TCP, UDP, and IP checksums
  in hardware.  The Linux kernel only offloads the TCP and UDP
  checksums (and always performs the pseudo header checksums), so
  the driver only supports checksumming for TCP/IP and UDP/IP
  packets.  Use ethtool to enable or disable this feature for RX
  and TX.
  
  VLAN
  
  In order to use VLAN, please consult Linux documentation on
  configuring VLANs.  The gianfar driver supports hardware insertion and
  extraction of VLAN headers, but not filtering.  Filtering will be
  done by the kernel.
  
  MULTICASTING
  
  The gianfar driver supports using the group hash table on the
  TSEC (and the extended hash table on the eTSEC) for multicast
  filtering.  On the eTSEC, the exact-match MAC registers are used
  before the hash tables.  See Linux documentation on how to join
  multicast groups.
  
  PADDING
  
  The gianfar driver supports padding received frames with 2 bytes
  to align the IP header to a 16-byte boundary, when supported by
  hardware.
  
  ETHTOOL
  
  The gianfar driver supports the use of ethtool for many
  configuration options.  You must run ethtool only on currently
  open interfaces.  See ethtool documentation for details.