[VAMOS] osmo-bts-trx: properly handle per-timeslot TSC values

Each timeslot can have its own Training Sequence Code value, which
may optionally be included in the NM_MT_SET_CHAN_ATTR message sent
over the A-bis/OML.  If it's not present, then the TSC value for a
timeslot is derived from the BCC part of BSIC, which is always
included in the NM_MT_SET_BTS_ATTR message.

On the TRXC interface, the BTS global TSC value is indicated to the
transceiver using either of the 'SETTSC' or 'SETBSIC' commands.
The transceiver then applies this value for all timeslots by default,
however it can be redefined for each timeslot individually using
additional arguments of the 'SETSLOT' command (see section 25.2.4.1
in the user manual [1] for more details).

Currently, trx_set_ts_as_pchan() sends TRX_PROV_EV_CFG_TSC to the
transceiver provisioning FSM, together with the per-timeslot TSC
value.  This event causes the FSM to modify the global TSC value,
that is going to be or has already been sent to the transceiver.
This is wrong, the global TSC value shall not be overwritten.

Remove the TRX_PROV_EV_CFG_TSC, and include per-timeslot Training
Sequence Code and Set in the data structure that gets passed together
with the TRX_PROV_EV_CFG_TS instead.  Implement handling of the
optional per-timeslot TSC in trx_if_cmd_setslot().

[1] https://downloads.osmocom.org/docs/latest/osmobts-usermanual.pdf

Change-Id: Idc5796151e3e83f42d60c2d4cb7c35890d76a7f5
Related: SYS#4895, OS#4941

1 files changed, 33 insertions, 40 deletions

diff --git a/src/osmo-bts-trx/trx_provision_fsm.c b/src/osmo-bts-trx/trx_provision_fsm.c
index 070037d0..5beca2ac 100644
--- a/src/osmo-bts-trx/trx_provision_fsm.c
+++ b/src/osmo-bts-trx/trx_provision_fsm.c
@@ -191,17 +191,15 @@ static void l1if_setslot_cb(struct trx_l1h *l1h, uint8_t tn, uint8_t type, int r
 	cb_ts_connected(ts, rc);
 }
 
-/* Returns true if any TS changed, false otherwise */
-static bool update_ts_data(struct trx_l1h *l1h, struct trx_prov_ev_cfg_ts_data* ts_data) {
-
-	if (l1h->config.slottype[ts_data->tn] != ts_data->slottype ||
-	    !l1h->config.slottype_valid[ts_data->tn]) {
-		l1h->config.slottype[ts_data->tn] = ts_data->slottype;
-		l1h->config.slottype_valid[ts_data->tn] = true;
-		l1h->config.slottype_sent[ts_data->tn] = false;
-		return true;
-	}
-	return false;
+static void update_ts_data(struct trx_l1h *l1h, struct trx_prov_ev_cfg_ts_data *data)
+{
+	l1h->config.setslot[data->tn].slottype = data->slottype;
+	l1h->config.setslot[data->tn].tsc_set = data->tsc_set;
+	l1h->config.setslot[data->tn].tsc_val = data->tsc_val;
+	l1h->config.setslot[data->tn].tsc_valid = data->tsc_valid;
+
+	l1h->config.setslot_valid[data->tn] = true;
+	l1h->config.setslot_sent[data->tn] = false;
 }
 
 /* Whether a given TRX is fully configured and can be powered on */
@@ -290,9 +288,7 @@ static void st_open_poweroff(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 	struct trx_l1h *l1h = (struct trx_l1h *)fi->priv;
 	struct phy_instance *pinst = l1h->phy_inst;
 	struct gsm_bts_trx *trx = pinst->trx;
-	uint8_t bsic;
 	uint16_t arfcn;
-	uint16_t tsc;
 	int nominal_power;
 	int status;
 	bool others_ready;
@@ -302,11 +298,21 @@ static void st_open_poweroff(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 		l1h->config.enabled =(bool)data;
 		break;
 	case TRX_PROV_EV_CFG_BSIC:
-		bsic = (uint8_t)(intptr_t)data;
-		if (l1h->config.bsic != bsic || !l1h->config.bsic_valid) {
-			l1h->config.bsic = bsic;
-			l1h->config.bsic_valid = true;
-			l1h->config.bsic_sent = false;
+		/* We always get BSIC from the BSC, TSC can be derived from the BCC */
+		if (!pinst->phy_link->u.osmotrx.use_legacy_setbsic) {
+			const uint8_t tsc = BSIC2BCC((uint8_t)(intptr_t)data);
+			if (l1h->config.tsc != tsc || !l1h->config.tsc_valid) {
+				l1h->config.tsc = tsc;
+				l1h->config.tsc_valid = true;
+				l1h->config.tsc_sent = false;
+			}
+		} else {
+			const uint8_t bsic = (uint8_t)(intptr_t)data;
+			if (l1h->config.bsic != bsic || !l1h->config.bsic_valid) {
+				l1h->config.bsic = bsic;
+				l1h->config.bsic_valid = true;
+				l1h->config.bsic_sent = false;
+			}
 		}
 		break;
 	case TRX_PROV_EV_CFG_ARFCN:
@@ -319,14 +325,6 @@ static void st_open_poweroff(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 			l1h->config.nomtxpower_sent = false;
 		}
 		break;
-	case TRX_PROV_EV_CFG_TSC:
-		tsc = (uint16_t)(intptr_t)data;
-		if (l1h->config.tsc != tsc || !l1h->config.tsc_valid) {
-			l1h->config.tsc = tsc;
-			l1h->config.tsc_valid = true;
-			l1h->config.tsc_sent = false;
-		}
-		break;
 	case TRX_PROV_EV_CFG_TS:
 		update_ts_data(l1h, (struct trx_prov_ev_cfg_ts_data*)data);
 		break;
@@ -478,11 +476,10 @@ static void st_open_poweron_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_sta
 	}
 
 	for (tn = 0; tn < TRX_NR_TS; tn++) {
-		if (l1h->config.slottype_valid[tn]
-		 && !l1h->config.slottype_sent[tn]) {
-			trx_if_cmd_setslot(l1h, tn,
-				l1h->config.slottype[tn], l1if_setslot_cb);
-			l1h->config.slottype_sent[tn] = true;
+		if (l1h->config.setslot_valid[tn]
+		 && !l1h->config.setslot_sent[tn]) {
+			trx_if_cmd_setslot(l1h, tn, l1if_setslot_cb);
+			l1h->config.setslot_sent[tn] = true;
 		}
 	}
 }
@@ -507,7 +504,7 @@ static void st_open_poweron(struct osmo_fsm_inst *fi, uint32_t event, void *data
 			l1h->config.maxdly_sent = false;
 			l1h->config.maxdlynb_sent = false;
 			for (tn = 0; tn < TRX_NR_TS; tn++)
-				l1h->config.slottype_sent[tn] = false;
+				l1h->config.setslot_sent[tn] = false;
 		} else if (!pinst->phy_link->u.osmotrx.poweronoff_sent) {
 			bts_model_trx_close_cb(pinst->trx, 0);
 		} /* else: poweroff in progress, cb will be called upon TRXC RSP */
@@ -519,12 +516,10 @@ static void st_open_poweron(struct osmo_fsm_inst *fi, uint32_t event, void *data
 		break;
 	case TRX_PROV_EV_CFG_TS:
 		ts_data = (struct trx_prov_ev_cfg_ts_data*)data;
-		if (update_ts_data(l1h, ts_data)) {
-			trx_if_cmd_setslot(l1h, ts_data->tn,
-				l1h->config.slottype[ ts_data->tn], l1if_setslot_cb);
-			l1h->config.slottype_sent[ts_data->tn] = true;
-		}
-
+		update_ts_data(l1h, ts_data);
+		/* While in this state we can send SETSLOT immediately */
+		trx_if_cmd_setslot(l1h, ts_data->tn, l1if_setslot_cb);
+		l1h->config.setslot_sent[ts_data->tn] = true;
 		break;
 	default:
 		OSMO_ASSERT(0);
@@ -571,7 +566,6 @@ static struct osmo_fsm_state trx_prov_fsm_states[] = {
 			X(TRX_PROV_EV_CFG_ENABLE) |
 			X(TRX_PROV_EV_CFG_BSIC) |
 			X(TRX_PROV_EV_CFG_ARFCN) |
-			X(TRX_PROV_EV_CFG_TSC) |
 			X(TRX_PROV_EV_CFG_TS) |
 			X(TRX_PROV_EV_RXTUNE_CNF) |
 			X(TRX_PROV_EV_TXTUNE_CNF) |
@@ -623,7 +617,6 @@ const struct value_string trx_prov_fsm_event_names[] = {
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_ENABLE),
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_BSIC),
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_ARFCN),
-	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_TSC),
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_TS),
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_RXGAIN),
 	OSMO_VALUE_STRING(TRX_PROV_EV_CFG_SETMAXDLY),