We re-use the 'wait_l1_conf' structure for implementing the
unacknowledge command window towards the PHY. This means that thre will
unconditionally be a 'wait_l1_conf' now, even for requests where the
caller didn't provide a call-back.
When re-starting OsmoBTS after unclean shutdown, the PHY is already
sending notifications (PH-DATA.ind, PH-TIME.ind, etc.) for the previous
physical channel / timeslot configuration. At the point those messages
are received, OsmoBTS might not even have A-bis OML up yet, and thus has
no clue how to process such messages (and subsequently likely crashes).
Let's block such primitives from passing further up the code until we
have received the TRX-OPEN response.
Harald Welte