TRX: prevent segfault upon phy init

Previously if multiply phy instances were configured but not used
osmo-bts-trx would segfault. Terminate with clear error message instead
so user can correct configuration. Example configuration which caused
problem:
...
phy 0
 instance 0
 instance 1
...
 trx 0
  phy 0 instance 0

Note the 2nd instance of phy 0 which is not used in trx later on.

Change-Id: Id979506731ea92401458f1060e87aeb690901539

2 files changed, 13 insertions, 7 deletions

diff --git a/src/common/scheduler.c b/src/common/scheduler.c
index db1f9770..fd5c5840 100644
--- a/src/common/scheduler.c
+++ b/src/common/scheduler.c
@@ -166,6 +166,9 @@ int trx_sched_init(struct l1sched_trx *l1t, struct gsm_bts_trx *trx)
 	uint8_t tn;
 	unsigned int i;
 
+	if (!trx)
+		return -EINVAL;
+
 	l1t->trx = trx;
 
 	LOGP(DL1C, LOGL_NOTICE, "Init scheduler for trx=%u\n", l1t->trx->nr);
diff --git a/src/osmo-bts-trx/l1_if.c b/src/osmo-bts-trx/l1_if.c
index 3d5f52e9..6304c1f5 100644
--- a/src/osmo-bts-trx/l1_if.c
+++ b/src/osmo-bts-trx/l1_if.c
@@ -71,19 +71,22 @@ struct trx_l1h *l1if_open(struct phy_instance *pinst)
 		return NULL;
 	l1h->phy_inst = pinst;
 
-	trx_sched_init(&l1h->l1s, pinst->trx);
+	rc = trx_sched_init(&l1h->l1s, pinst->trx);
+	if (rc < 0) {
+		LOGP(DL1C, LOGL_FATAL, "Cannot initialize scheduler for phy "
+		     "instance %d\n", pinst->num);
+		return NULL;
+	}
 
 	rc = trx_if_open(l1h);
 	if (rc < 0) {
-		LOGP(DL1C, LOGL_FATAL, "Cannot initialize scheduler\n");
-		goto err;
+		LOGP(DL1C, LOGL_FATAL, "Cannot open TRX interface for phy "
+		     "instance %d\n", pinst->num);
+		l1if_close(l1h);
+		return NULL;
 	}
 
 	return l1h;
-
-err:
-	l1if_close(l1h);
-	return NULL;
 }
 
 void l1if_close(struct trx_l1h *l1h)