cosmetic: FSMs: allow ignorable events

In various FSMs, some events may appear later or earlier without need of
action. Do not indicate these as 'ERROR' (event not permitted), but allow and
ignore them.

Debug-log about some of those.

From the old code, we've taken over the habit to change into
WAIT_BEFORE_RF_RELEASE even before SAPI[0] is released. Hence we may still
receive a SAPI[0] REL_IND in WAIT_BEFORE_RF_RELEASE. Don't show this as error
message, just silently accept it.

Change-Id: Ie320c7c6a1436184aaf2ec5a1843e04f4b3414ab

1 files changed, 38 insertions, 2 deletions

diff --git a/src/osmo-bsc/lchan_fsm.c b/src/osmo-bsc/lchan_fsm.c
index 7a9f57fb2..9f053ac4a 100644
--- a/src/osmo-bsc/lchan_fsm.c
+++ b/src/osmo-bsc/lchan_fsm.c
@@ -755,7 +755,11 @@ static void lchan_fsm_wait_mgw_endpoint_available(struct osmo_fsm_inst *fi, uint
 	case LCHAN_EV_MGW_ENDPOINT_AVAILABLE:
 		lchan->activate.mgw_endpoint_available = true;
 		lchan_fsm_tch_post_endpoint_available(fi);
-		break;
+		return;
+
+	case LCHAN_EV_RLL_ESTABLISH_IND:
+		/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
+		return;
 
 	default:
 		OSMO_ASSERT(false);
@@ -828,6 +832,10 @@ static void lchan_fsm_wait_ipacc_crcx_ack(struct osmo_fsm_inst *fi, uint32_t eve
 		lchan_fail("Received NACK on IPACC CRCX");
 		return;
 
+	case LCHAN_EV_RLL_ESTABLISH_IND:
+		/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
+		return;
+
 	default:
 		OSMO_ASSERT(false);
 	}
@@ -879,6 +887,10 @@ static void lchan_fsm_wait_ipacc_mdcx_ack(struct osmo_fsm_inst *fi, uint32_t eve
 		lchan_fail("Received NACK on IPACC MDCX");
 		return;
 
+	case LCHAN_EV_RLL_ESTABLISH_IND:
+		/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
+		return;
+
 	default:
 		OSMO_ASSERT(false);
 	}
@@ -946,6 +958,10 @@ static void lchan_fsm_wait_mgw_endpoint_configured(struct osmo_fsm_inst *fi, uin
 		lchan_fail("Error while redirecting the MGW to the BTS' RTP port");
 		return;
 
+	case LCHAN_EV_RLL_ESTABLISH_IND:
+		/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
+		return;
+
 	default:
 		OSMO_ASSERT(false);
 	}
@@ -1033,7 +1049,19 @@ static void handle_rll_rel_ind_or_conf(struct osmo_fsm_inst *fi, uint32_t event,
 
 static void lchan_fsm_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 {
-	handle_rll_rel_ind_or_conf(fi, event, data, true);
+	switch (event) {
+	case LCHAN_EV_RLL_ESTABLISH_IND:
+		/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
+		return;
+
+	case LCHAN_EV_RLL_REL_IND:
+	case LCHAN_EV_RLL_REL_CONF:
+		handle_rll_rel_ind_or_conf(fi, event, data, true);
+		return;
+
+	default:
+		OSMO_ASSERT(false);
+	}
 }
 
 static bool should_sacch_deact(struct gsm_lchan *lchan)
@@ -1236,6 +1264,7 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 		.action = lchan_fsm_wait_mgw_endpoint_available,
 		.in_event_mask = 0
 			| S(LCHAN_EV_MGW_ENDPOINT_AVAILABLE)
+			| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
@@ -1252,6 +1281,7 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 		.in_event_mask = 0
 			| S(LCHAN_EV_IPACC_CRCX_ACK)
 			| S(LCHAN_EV_IPACC_CRCX_NACK)
+			| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
@@ -1267,6 +1297,7 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 		.in_event_mask = 0
 			| S(LCHAN_EV_IPACC_MDCX_ACK)
 			| S(LCHAN_EV_IPACC_MDCX_NACK)
+			| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
@@ -1281,6 +1312,7 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 		.action = lchan_fsm_wait_mgw_endpoint_configured,
 		.in_event_mask = 0
 			| S(LCHAN_EV_MGW_ENDPOINT_CONFIGURED)
+			| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
@@ -1296,6 +1328,7 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 		.in_event_mask = 0
 			| S(LCHAN_EV_RLL_REL_IND)
 			| S(LCHAN_EV_RLL_REL_CONF)
+			| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
@@ -1320,6 +1353,9 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 	},
 	[LCHAN_ST_WAIT_BEFORE_RF_RELEASE] = {
 		.name = "WAIT_BEFORE_RF_RELEASE",
+		.in_event_mask = 0
+			| S(LCHAN_EV_RLL_REL_IND) /* allow late REL_IND of SAPI[0] */
+			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_UNUSED)
 			| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)