ECU in UL path: move state alloc/free to l1sap

In preparation for moving the now-optional application of ECU in UL
path from osmo-bts-trx model-specific code to the common layer,
move ECU state allocation and freeing from trx model to l1sap.

Related: OS#6040
Change-Id: Ic98a2eb26b5a99bc4a89ad07ae87c9a86b921418

2 files changed, 26 insertions, 20 deletions

diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index 528a7356..981d3bc8 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -2208,6 +2208,13 @@ int l1sap_chan_act(struct gsm_bts_trx *trx, uint8_t chan_nr)
 	if (rc)
 		return -RSL_ERR_EQUIPMENT_FAIL;
 
+	/* Is it TCH?  If it is, attempt to allocate an Error Concealment Unit
+	 * instance, if available, unless it is disabled by vty config. */
+	if (lchan_is_tch(lchan) && trx->bts->use_ul_ecu)
+		lchan->ecu_state = osmo_ecu_init(trx, lchan2ecu_codec(lchan));
+	else
+		lchan->ecu_state = NULL;
+
 	/* Init DTX DL FSM if necessary */
 	if (trx->bts->dtxd && lchan_is_tch(lchan)) {
 		lchan->tch.dtx.dl_amr_fsm = osmo_fsm_inst_alloc(&dtx_dl_amr_fsm,
@@ -2248,6 +2255,12 @@ int l1sap_chan_rel(struct gsm_bts_trx *trx, uint8_t chan_nr)
 		lchan->tch.dtx.dl_amr_fsm = NULL;
 	}
 
+	/* clear ECU state (if any) */
+	if (lchan->ecu_state) {
+		osmo_ecu_destroy(lchan->ecu_state);
+		lchan->ecu_state = NULL;
+	}
+
 	return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_DEACTIVATE,
 		0);
 }
@@ -2270,5 +2283,18 @@ int l1sap_chan_modify(struct gsm_bts_trx *trx, uint8_t chan_nr)
 	LOGPLCHAN(lchan, DL1C, LOGL_INFO, "Modifying channel %s\n",
 		rsl_chan_nr_str(chan_nr));
 
+	/* Is it TCH?  If it is and we are applying internal uplink ECUs,
+	 * the new channel mode calls for a different ECU.  Any changes
+	 * in vty config (enabling or disabling this ECU application)
+	 * will also take effect upon channel modification. */
+	if (lchan_is_tch(lchan)) {
+		if (lchan->ecu_state)
+			osmo_ecu_destroy(lchan->ecu_state);
+		if (trx->bts->use_ul_ecu)
+			lchan->ecu_state = osmo_ecu_init(trx, lchan2ecu_codec(lchan));
+		else
+			lchan->ecu_state = NULL;
+	}
+
 	return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_MODIFY, 0);
 }
diff --git a/src/osmo-bts-trx/l1_if.c b/src/osmo-bts-trx/l1_if.c
index 69ee117e..60f92325 100644
--- a/src/osmo-bts-trx/l1_if.c
+++ b/src/osmo-bts-trx/l1_if.c
@@ -439,14 +439,6 @@ int bts_model_l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
 				break;
 			}
 
-			/* Attempt to allocate an Error Concealment Unit
-			 * instance, if available, unless it is disabled
-			 * by the vty config. */
-			if (trx->bts->use_ul_ecu)
-				lchan->ecu_state = osmo_ecu_init(trx, lchan2ecu_codec(lchan));
-			else
-				lchan->ecu_state = NULL;
-
 			/* activate dedicated channel */
 			trx_sched_set_lchan(lchan, chan_nr, LID_DEDIC, true);
 			/* activate associated channel */
@@ -475,13 +467,6 @@ int bts_model_l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
 			mph_info_chan_confirm(trx, chan_nr, PRIM_INFO_ACTIVATE, 0);
 			break;
 		case PRIM_INFO_MODIFY:
-			/* ECU for possibly new codec */
-			if (lchan->ecu_state)
-				osmo_ecu_destroy(lchan->ecu_state);
-			if (trx->bts->use_ul_ecu)
-				lchan->ecu_state = osmo_ecu_init(trx, lchan2ecu_codec(lchan));
-			else
-				lchan->ecu_state = NULL;
 			/* change mode */
 			trx_sched_set_mode(lchan->ts, chan_nr,
 					   lchan->rsl_cmode, lchan->tch_mode,
@@ -507,11 +492,6 @@ int bts_model_l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
 				rc = -EPERM;
 				break;
 			}
-			/* clear ECU state (if any) */
-			if (lchan->ecu_state) {
-				osmo_ecu_destroy(lchan->ecu_state);
-				lchan->ecu_state = NULL;
-			}
 			/* deactivate associated channel */
 			bts_model_lchan_deactivate_sacch(lchan);
 			if (!l1sap->u.info.u.act_req.sacch_only) {