fixes a TX hang bug that it could happen when if_start callback didn't
be restarted by full of the output queue.
Tested by: bsduser <bsd at acd.homelinux.org>
MFC r198099:
fixes a TX hang that could be possible to happen when the trasfers are
in the high speed that some drivers don't call if_start callback after
marking ~IFF_DRV_OACTIVE.
Approved by: re (kib)
IF_ADDR_UNLOCK() across network device drivers when accessing the
per-interface multicast address list, if_multiaddrs. This will
allow us to change the locking strategy without affecting our driver
programming interface or binary interface.
For two wireless drivers, remove unnecessary locking, since they
don't actually access the multicast address list.
Approved by: re (kib)
MFC after: 6 weeks
