Fix TSC/BSIC handling bug and remove bts->tsc

This fixes a bug in the following circumstances:
* BSIC is set to 0 in the config file
* No TSC is explicitly specified at the BST level in the config file

In this case, we ended up using BSIC=0 and TSC=7, as TSC=7 is our
default initialization value.

The TSC of the CCCH/BCCH must always be the BCC, which is the lower 3
bits of the BSIC.  Having configuration options for both the BSIC _and_
the TSC at the BTS level therefore makes no sense, as it only adds ways
in which users can configure non-oprational configurations.  So we
remove the bts->tsc member, and keep only the ts->tsc members that allow
us to configure a timeslot-specific TSC that's different from the BTS
TSC (= BCC).

7 files changed, 15 insertions, 37 deletions

diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index c167c494a..6d7aba358 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -437,7 +437,7 @@ void subscr_con_free(struct gsm_subscriber_connection *conn);
 
 struct gsm_bts *gsm_bts_alloc_register(struct gsm_network *net,
 					enum gsm_bts_type type,
-					uint8_t tsc, uint8_t bsic);
+					uint8_t bsic);
 
 void set_ts_e1link(struct gsm_bts_trx_ts *ts, uint8_t e1_nr,
 		   uint8_t e1_ts, uint8_t e1_ts_ss);
diff --git a/openbsc/include/openbsc/gsm_data_shared.h b/openbsc/include/openbsc/gsm_data_shared.h
index be3333ca1..1b7382d5c 100644
--- a/openbsc/include/openbsc/gsm_data_shared.h
+++ b/openbsc/include/openbsc/gsm_data_shared.h
@@ -50,7 +50,6 @@ enum gsm_chreq_reason_t {
 #define TS_MAX_LCHAN	8
 
 #define HARDCODED_ARFCN 123
-#define HARDCODED_TSC	7
 #define HARDCODED_BSIC	0x3f	/* NCC = 7 / BCC = 7 */
 
 /* for multi-drop config */
@@ -569,9 +568,8 @@ struct gsm_bts {
 	uint16_t cell_identity;
 	/* location area code of this BTS */
 	uint16_t location_area_code;
-	/* Training Sequence Code */
-	uint8_t tsc;
-	/* Base Station Identification Code (BSIC) */
+	/* Base Station Identification Code (BSIC), lower 3 bits is BCC,
+	 * which is used as TSC for the CCCH */
 	uint8_t bsic;
 	/* type of BTS */
 	enum gsm_bts_type type;
@@ -798,7 +796,7 @@ static inline uint8_t gsm_ts_tsc(const struct gsm_bts_trx_ts *ts)
 	if (ts->tsc != -1)
 		return ts->tsc;
 	else
-		return ts->trx->bts->tsc;
+		return ts->trx->bts->bsic & 7;
 }
 
 
diff --git a/openbsc/src/ipaccess/ipaccess-config.c b/openbsc/src/ipaccess/ipaccess-config.c
index c42c7bb9c..31da05636 100644
--- a/openbsc/src/ipaccess/ipaccess-config.c
+++ b/openbsc/src/ipaccess/ipaccess-config.c
@@ -987,7 +987,7 @@ int main(int argc, char **argv)
 	if (!bsc_gsmnet)
 		exit(1);
 
-	bts = gsm_bts_alloc_register(bsc_gsmnet, GSM_BTS_TYPE_NANOBTS, HARDCODED_TSC,
+	bts = gsm_bts_alloc_register(bsc_gsmnet, GSM_BTS_TYPE_NANOBTS,
 				     HARDCODED_BSIC);
 	/* ip.access supports up to 4 chained TRX */
 	gsm_bts_trx_alloc(bts);
diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c
index 9c19ec91c..743f4c155 100644
--- a/openbsc/src/libbsc/bsc_init.c
+++ b/openbsc/src/libbsc/bsc_init.c
@@ -280,10 +280,10 @@ static void bootstrap_rsl(struct gsm_bts_trx *trx)
 	unsigned int i;
 
 	LOGP(DRSL, LOGL_NOTICE, "bootstrapping RSL for BTS/TRX (%u/%u) "
-		"on ARFCN %u using MCC=%u MNC=%u LAC=%u CID=%u BSIC=%u TSC=%u\n",
+		"on ARFCN %u using MCC=%u MNC=%u LAC=%u CID=%u BSIC=%u\n",
 		trx->bts->nr, trx->nr, trx->arfcn, bsc_gsmnet->country_code,
 		bsc_gsmnet->network_code, trx->bts->location_area_code,
-		trx->bts->cell_identity, trx->bts->bsic, trx->bts->tsc);
+		trx->bts->cell_identity, trx->bts->bsic);
 
 	if (trx->bts->type == GSM_BTS_TYPE_NOKIA_SITE) {
 		rsl_nokia_si_begin(trx);
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 24bae9799..306fff02e 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -253,10 +253,10 @@ static void bts_dump_vty(struct vty *vty, struct gsm_bts *bts)
 	struct pchan_load pl;
 
 	vty_out(vty, "BTS %u is of %s type in band %s, has CI %u LAC %u, "
-		"BSIC %u, TSC %u and %u TRX%s",
+		"BSIC %u and %u TRX%s",
 		bts->nr, btstype2str(bts->type), gsm_band_name(bts->band),
 		bts->cell_identity,
-		bts->location_area_code, bts->bsic, bts->tsc,
+		bts->location_area_code, bts->bsic,
 		bts->num_trx, VTY_NEWLINE);
 	vty_out(vty, "Description: %s%s",
 		bts->description ? bts->description : "(null)", VTY_NEWLINE);
@@ -374,7 +374,7 @@ static void config_write_e1_link(struct vty *vty, struct gsm_e1_subslot *e1_link
 static void config_write_ts_single(struct vty *vty, struct gsm_bts_trx_ts *ts)
 {
 	vty_out(vty, "    timeslot %u%s", ts->nr, VTY_NEWLINE);
-	if (ts->tsc != -1 && ts->tsc != ts->trx->bts->tsc)
+	if (ts->tsc != -1)
 		vty_out(vty, "     training_sequence_code %u%s", ts->tsc, VTY_NEWLINE);
 	if (ts->pchan != GSM_PCHAN_NONE)
 		vty_out(vty, "     phys_chan_config %s%s",
@@ -550,9 +550,6 @@ static void config_write_bts_single(struct vty *vty, struct gsm_bts *bts)
 	vty_out(vty, "  location_area_code %u%s", bts->location_area_code,
 		VTY_NEWLINE);
 	vty_out(vty, "  base_station_id_code %u%s", bts->bsic, VTY_NEWLINE);
-	if (bts->tsc != (bts->bsic & 7))
-		vty_out(vty, "  training_sequence_code %u%s", bts->tsc,
-			VTY_NEWLINE);
 	if (bts->tz.override != 0) {
 		if (bts->tz.dst)
 			vty_out(vty, "  timezone %d %d %d%s",
@@ -1617,7 +1614,7 @@ DEFUN(cfg_bts,
 	} else if (bts_nr == gsmnet->num_bts) {
 		/* allocate a new one */
 		bts = gsm_bts_alloc_register(gsmnet, GSM_BTS_TYPE_UNKNOWN,
-					     HARDCODED_TSC, HARDCODED_BSIC);
+					     HARDCODED_BSIC);
 	} else
 		bts = gsm_bts_num(gsmnet, bts_nr);
 
@@ -1712,23 +1709,12 @@ DEFUN(cfg_bts_lac,
 }
 
 
-DEFUN(cfg_bts_tsc,
+/* compatibility wrapper for old config files */
+DEFUN_HIDDEN(cfg_bts_tsc,
       cfg_bts_tsc_cmd,
       "training_sequence_code <0-7>",
       "Set the Training Sequence Code (TSC) of this BTS\n" "TSC\n")
 {
-	struct gsm_bts *bts = vty->index;
-	int tsc = atoi(argv[0]);
-
-	if (!gsm_bts_has_feature(bts, BTS_FEAT_MULTI_TSC)) {
-		vty_out(vty, "%% This BTS does not support a TSC != BCC, "
-			"falling back to BCC%s", VTY_NEWLINE);
-		bts->tsc = bts->bsic & 7;
-		return CMD_WARNING;
-	}
-
-	bts->tsc = tsc;
-
 	return CMD_SUCCESS;
 }
 
@@ -1748,11 +1734,6 @@ DEFUN(cfg_bts_bsic,
 	}
 	bts->bsic = bsic;
 
-	/* automatically re-configuer the TSC if we change the BCC
-	 * which is the lower 3 bits of the BSIC */
-	if (!gsm_bts_has_feature(bts, BTS_FEAT_MULTI_TSC))
-		bts->tsc = bts->bsic & 7;
-
 	return CMD_SUCCESS;
 }
 
diff --git a/openbsc/src/libcommon/gsm_data.c b/openbsc/src/libcommon/gsm_data.c
index 4ce4ecac7..16035edcc 100644
--- a/openbsc/src/libcommon/gsm_data.c
+++ b/openbsc/src/libcommon/gsm_data.c
@@ -294,7 +294,7 @@ int gsm_set_bts_type(struct gsm_bts *bts, enum gsm_bts_type type)
 }
 
 struct gsm_bts *gsm_bts_alloc_register(struct gsm_network *net, enum gsm_bts_type type,
-					uint8_t tsc, uint8_t bsic)
+					uint8_t bsic)
 {
 	struct gsm_bts_model *model = bts_model_find(type);
 	struct gsm_bts *bts;
@@ -310,7 +310,6 @@ struct gsm_bts *gsm_bts_alloc_register(struct gsm_network *net, enum gsm_bts_typ
 	bts->nr = net->num_bts++;
 	bts->type = type;
 	bts->model = model;
-	bts->tsc = tsc;
 	bts->bsic = bsic;
 
 	bts->neigh_list_manual_mode = 0;
diff --git a/openbsc/src/utils/bs11_config.c b/openbsc/src/utils/bs11_config.c
index e8acb461a..0d13e25c5 100644
--- a/openbsc/src/utils/bs11_config.c
+++ b/openbsc/src/utils/bs11_config.c
@@ -898,7 +898,7 @@ int main(int argc, char **argv)
 		fprintf(stderr, "Unable to allocate gsm network\n");
 		exit(1);
 	}
-	g_bts = gsm_bts_alloc_register(gsmnet, GSM_BTS_TYPE_BS11, HARDCODED_TSC,
+	g_bts = gsm_bts_alloc_register(gsmnet, GSM_BTS_TYPE_BS11,
 					HARDCODED_BSIC);
 
 	/* Override existing OML callback handler to set our own. */