make sure channel mode and s15_s0 are updated only after an ACK

I noticed during testing that an lchan used as TCH/F in fact still had
its channel mode set to Signalling -- because on Assignment, the Speech
mode used to be placed in the *previous* lchan and the new lchan was
never updated after the Activ ACK. This is unbearable confusion which I
complained about numerous times, so far mostly for cosmetic reasons. But
implementing re-assignment properly actually requires this to be cleaned
up.

Keep all volatile chan mode settings in lchan->activate.* or
lchan->modify.*, and only update lchan->* members when an ACK has been
received for those settings. So a failed request keeps a sane state.

Make sure that those settings are in fact updated in the proper lchan,
upon an ACK, so that subsequent re-assignment or mode-modify know the
accurate lchan state.

Related are upcoming patches that sort out the AMR multirate
configuration in a similar fashion, see
Iebac2dc26412d877e5364f90d6f2ed7a7952351e
Ia7519d2fa9e7f0b61b222d27d077bde4660c40b9
Ie57f9d0e3912632903d9740291225bfd1634ed47.

Related: SYS#5315 OS#4940 OS#3787 OS#3833
Change-Id: Ie0da36124d73efc28a8809b63d7c96e2167fc412

1 files changed, 13 insertions, 11 deletions

diff --git a/src/osmo-bsc/handover_decision_2.c b/src/osmo-bsc/handover_decision_2.c
index 3326c0bb6..5b7d4b16c 100644
--- a/src/osmo-bsc/handover_decision_2.c
+++ b/src/osmo-bsc/handover_decision_2.c
@@ -52,7 +52,7 @@
 	     lchan->ts->nr, \
 	     lchan->nr, \
 	     gsm_lchant_name(lchan->type), \
-	     gsm48_chan_mode_name(lchan->tch_mode), \
+	     gsm48_chan_mode_name(lchan->current_ch_mode_rate.chan_mode), \
 	     bsc_subscr_name(lchan->conn? lchan->conn->bsub : NULL), \
 	     ## args)
 
@@ -63,7 +63,7 @@
 	     lchan->ts->nr, \
 	     lchan->nr, \
 	     gsm_lchant_name(lchan->type), \
-	     gsm48_chan_mode_name(lchan->tch_mode), \
+	     gsm48_chan_mode_name(lchan->current_ch_mode_rate.chan_mode), \
 	     new_bts->nr, \
 	     bsc_subscr_name(lchan->conn? lchan->conn->bsub : NULL), \
 	     ## args)
@@ -75,7 +75,7 @@
 	     lchan->ts->nr, \
 	     lchan->nr, \
 	     gsm_lchant_name(lchan->type), \
-	     gsm48_chan_mode_name(lchan->tch_mode), \
+	     gsm48_chan_mode_name(lchan->current_ch_mode_rate.chan_mode), \
 	     gsm0808_cell_id_list_name(remote_cil), \
 	     bsc_subscr_name(lchan->conn? lchan->conn->bsub : NULL), \
 	     ## args)
@@ -478,7 +478,7 @@ static void check_requirements(struct ho_candidate *c)
 
 	/* compatibility check for codecs.
 	 * if so, the candidates for full rate and half rate are selected */
-	switch (c->current.lchan->tch_mode) {
+	switch (c->current.lchan->current_ch_mode_rate.chan_mode) {
 	case GSM48_CMODE_SPEECH_V1:
 		switch (c->current.lchan->type) {
 		case GSM_LCHAN_TCH_F: /* mandatory */
@@ -489,7 +489,7 @@ static void check_requirements(struct ho_candidate *c)
 				LOGPHOLCHANTOBTS(c->current.lchan, c->target.bts, LOGL_DEBUG,
 						 "tch_mode='%s' type='%s' not supported\n",
 						 get_value_string(gsm48_chan_mode_names,
-								  c->current.lchan->tch_mode),
+								  c->current.lchan->current_ch_mode_rate.chan_mode),
 						 gsm_lchant_name(c->current.lchan->type));
 				break;
 			}
@@ -498,7 +498,8 @@ static void check_requirements(struct ho_candidate *c)
 			break;
 		default:
 			LOGPHOLCHAN(c->current.lchan, LOGL_ERROR, "Unexpected channel type: neither TCH/F nor TCH/H for %s\n",
-				    get_value_string(gsm48_chan_mode_names, c->current.lchan->tch_mode));
+				    get_value_string(gsm48_chan_mode_names,
+						     c->current.lchan->current_ch_mode_rate.chan_mode));
 			return;
 		}
 		break;
@@ -757,7 +758,7 @@ static void check_requirements_remote_bss(struct ho_candidate *c)
 
 	/* compatibility check for codecs -- we have no notion of what the remote BSS supports. We can
 	 * only assume that a handover would work, and use only the local requirements. */
-	switch (c->current.lchan->tch_mode) {
+	switch (c->current.lchan->current_ch_mode_rate.chan_mode) {
 	case GSM48_CMODE_SPEECH_V1:
 		switch (c->current.lchan->type) {
 		case GSM_LCHAN_TCH_F: /* mandatory */
@@ -769,7 +770,8 @@ static void check_requirements_remote_bss(struct ho_candidate *c)
 			break;
 		default:
 			LOGPHOLCHAN(c->current.lchan, LOGL_ERROR, "Unexpected channel type: neither TCH/F nor TCH/H for %s\n",
-				    get_value_string(gsm48_chan_mode_names, c->current.lchan->tch_mode));
+				    get_value_string(gsm48_chan_mode_names,
+						     c->current.lchan->current_ch_mode_rate.chan_mode));
 			return;
 		}
 		break;
@@ -815,7 +817,7 @@ static int trigger_local_ho_or_as(struct ho_candidate *c, uint8_t requirements)
 	bool full_rate = false;
 
 	/* afs_bias becomes > 0, if AFS is used and is improved */
-	if (c->current.lchan->tch_mode == GSM48_CMODE_SPEECH_AMR)
+	if (c->current.lchan->current_ch_mode_rate.chan_mode == GSM48_CMODE_SPEECH_AMR)
 		afs_bias = ho_get_hodec2_afs_bias_rxlev(c->target.bts->ho);
 
 	/* select TCH rate, prefer TCH/F if AFS is improved */
@@ -1243,7 +1245,7 @@ static void collect_candidates_for_lchan(struct gsm_lchan *lchan,
 static int find_alternative_lchan(struct gsm_lchan *lchan, bool include_weaker_rxlev)
 {
 	struct gsm_bts *bts = lchan->ts->trx->bts;
-	int ahs = (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR
+	int ahs = (lchan->current_ch_mode_rate.chan_mode == GSM48_CMODE_SPEECH_AMR
 		   && lchan->type == GSM_LCHAN_TCH_H);
 	int rxlev_current;
 	struct ho_candidate clist[1 + ARRAY_SIZE(lchan->neigh_meas)];
@@ -1451,7 +1453,7 @@ static void on_measurement_report(struct gsm_meas_rep *mr)
 
 	/* improve levels in case of AFS, if defined */
 	if (lchan->type == GSM_LCHAN_TCH_F
-	 && lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) {
+	 && lchan->current_ch_mode_rate.chan_mode == GSM48_CMODE_SPEECH_AMR) {
 		int av_rxlev_was = av_rxlev;
 		int av_rxqual_was = av_rxqual;
 		int rxlev_bias = ho_get_hodec2_afs_bias_rxlev(bts->ho);