As discussed in this thread:

http://www.mail-archive.com/netdev@vger.kernel.org/msg53976.html

promiscous mode means to disable *all* filters. Currently only unicast
and multicast filtering is disabled. This patch changes all Intel
drivers to also disable VLAN filtering.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>