before adding/removing packets from the queue. Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.
IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue. An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.
Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.
This driver should support both the SSI (V.35 etc) E1/T1 unchannelized,
DS3 and HSSI cards. Only tested on the SSI card.
More info at: http://www.lanmedia.com
Thanks to LanMedia for donating two LMC1000P cards.
if_de.c driver modified by: LanMedia
NetGraphification by: Stephen Kiernan <sk-ports@vegamuse.org>