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, 8 insertions, 8 deletions

diff --git a/src/osmo-bsc/handover_fsm.c b/src/osmo-bsc/handover_fsm.c
index 0b5a8be51..b7658c578 100644
--- a/src/osmo-bsc/handover_fsm.c
+++ b/src/osmo-bsc/handover_fsm.c
@@ -61,7 +61,7 @@
 		lchan ? lchan->ts->nr : 0, \
 		lchan ? gsm_lchant_name(lchan->type) : "?", \
 		lchan ? lchan->nr : 0, \
-		lchan ? gsm48_chan_mode_name(lchan->tch_mode) : "?"
+		lchan ? gsm48_chan_mode_name(lchan->current_ch_mode_rate.chan_mode) : "?"
 
 #define LOG_FMT_TO_LCHAN "%u-%u-%u-%s%s%s-%u"
 #define LOG_ARGS_TO_LCHAN(lchan) \
@@ -398,14 +398,14 @@ static void handover_start_intra_bsc(struct gsm_subscriber_connection *conn)
 	info = (struct lchan_activate_info){
 		.activ_for = ACTIVATE_FOR_HANDOVER,
 		.for_conn = conn,
-		.chan_mode = conn->lchan->tch_mode,
+		.ch_mode_rate = conn->lchan->current_ch_mode_rate,
 		.encr = conn->lchan->encr,
 		.requires_voice_stream = conn->lchan->mgw_endpoint_ci_bts ? true : false,
 		.msc_assigned_cic = conn->ho.inter_bsc_in.msc_assigned_cic,
 		.re_use_mgw_endpoint_from_lchan = conn->lchan,
 		.wait_before_switching_rtp = true,
-		.s15_s0 = conn->lchan->activate.info.s15_s0,
 	};
+	info.ch_mode_rate.chan_rate = chan_t_to_chan_rate(ho->new_lchan->type);
 
 	/* For intra-cell handover, we know the accurate Timing Advance from the previous lchan. For inter-cell
 	 * handover, no Timing Advance for the new cell is known, so leave it unset. */
@@ -696,8 +696,7 @@ void handover_start_inter_bsc_in(struct gsm_subscriber_connection *conn,
 	info = (struct lchan_activate_info){
 		.activ_for = ACTIVATE_FOR_HANDOVER,
 		.for_conn = conn,
-		.chan_mode = ch_mode_rate.chan_mode,
-		.s15_s0 = ch_mode_rate.s15_s0,
+		.ch_mode_rate = ch_mode_rate,
 		.requires_voice_stream = chan_mode_is_tch(ch_mode_rate.chan_mode),
 		.msc_assigned_cic = req->msc_assigned_cic,
 	};
@@ -849,7 +848,7 @@ static void send_handover_performed(struct gsm_subscriber_connection *conn)
 	};
 
 	/* Chosen Channel 3.2.2.33 */
-	ho_perf_params.chosen_channel = gsm0808_chosen_channel(lchan->type, lchan->tch_mode);
+	ho_perf_params.chosen_channel = gsm0808_chosen_channel(lchan->type, lchan->current_ch_mode_rate.chan_mode);
 	if (!ho_perf_params.chosen_channel) {
 		LOG_HO(conn, LOGL_ERROR, "Failed to generate Chosen Channel IE, can't send HANDOVER PERFORMED!\n");
 		return;
@@ -862,14 +861,15 @@ static void send_handover_performed(struct gsm_subscriber_connection *conn)
 
 	if (ho->new_lchan->activate.info.requires_voice_stream) {
 		/* Speech Version (chosen) 3.2.2.51 */
-		ho_perf_params.speech_version_chosen = gsm0808_permitted_speech(lchan->type, lchan->tch_mode);
+		ho_perf_params.speech_version_chosen = gsm0808_permitted_speech(lchan->type,
+										lchan->current_ch_mode_rate.chan_mode);
 		ho_perf_params.speech_version_chosen_present = true;
 
 		/* Speech Codec (chosen) 3.2.2.104 */
 		if (gscon_is_aoip(conn)) {
 			/* Extrapolate speech codec from speech mode */
 			gsm0808_speech_codec_from_chan_type(&sc, ho_perf_params.speech_version_chosen);
-			sc.cfg = conn->lchan->ch_mode_rate.s15_s0;
+			sc.cfg = conn->lchan->current_ch_mode_rate.s15_s0;
 			memcpy(&ho_perf_params.speech_codec_chosen, &sc, sizeof(sc));
 			ho_perf_params.speech_codec_chosen_present = true;
 		}