bts-trx: Time out if no clock ind recvd after RSP POWERON

Before this patch, if due to whatever reason the TRX started fine (RSP
POWERON 0) and sockets were created but no CLOCK IND was ever received
by the BTS, it wouldn't notice since the timerfd timeouts
(bts_shutdown("no clock")) are only checked after the first CLOCK IND is
sent by the TRX.
As a result, the BTS would be kept on forever saying everything is fine
but it would be sending no DL burst at all to the TRX (tested with a
modfied osmo-trx dropping clock indication).
With this patch, new APIs are added to indicate the scheduler_trx code
the timeframes where clock ind are expected (between RSP POWERON 0 and
RSP POWEROFF 0); if TRX sends clock indications out of that timeframe,
BTs lower layers will drop them (controlled by "powered" bool).
Hence, the scheduler_trx can now place a timeout (reusing same timerfd
because its new use is exclusive in time with its other previous use)
when it is told that CLOCK IND should start appearing, and if none
arrives in considerable time, then the BTS can be shut down to notify
the rest of the network.

Related: OS#4215
Change-Id: Iba5dbe867aff10e70ec73dbf1f7aeeecb15c0a4d

1 files changed, 6 insertions, 0 deletions

diff --git a/include/osmo-bts/scheduler.h b/include/osmo-bts/scheduler.h
index e693e3ec..3100a1da 100644
--- a/include/osmo-bts/scheduler.h
+++ b/include/osmo-bts/scheduler.h
@@ -175,6 +175,12 @@ int trx_sched_tch_req(struct l1sched_trx *l1t, struct osmo_phsap_prim *l1sap);
 /*! \brief PHY informs us of new (current) GSM frame number */
 int trx_sched_clock(struct gsm_bts *bts, uint32_t fn);
 
+/*! \brief PHY informs us clock indications should start to be received */
+int trx_sched_clock_started(struct gsm_bts *bts);
+
+/*! \brief PHY informs us no more clock indications should be received anymore */
+int trx_sched_clock_stopped(struct gsm_bts *bts);
+
 /*! \brief set multiframe scheduler to given physical channel config */
 int trx_sched_set_pchan(struct l1sched_trx *l1t, uint8_t tn,
         enum gsm_phys_chan_config pchan);