ensure that acc_ramp_init() is only called once

There are plans to register signal handlers in acc_ramp_init(). Once we
do that, the acc_ramp_init() function should only be called once to
avoid duplicate signal handlers on the handler list.

However, the acc_ramp_init() function currently serves a dual-purpose:

1) Initialize the acc_ramp structure for a bts
2) Enable or disable ACC ramping

Add new functions to support use case 2, and call acc_ramp_init()
just once while reading the configuration file. The VTY commands
which enable/disable ACC ramping use the new APIs instead.

Also, rename acc_ramp_start() to acc_ramp_trigger() and tweak its
semantics so that it can always be called regardless of what the
current configuration settings are. This prepares us for triggering
ACC ramping upon events other than "RSL link-up".

This is a port of osmo-bsc commit ea33341cf7b52d432be98f2280b4a5f3129ef667.
Also remove a call to acc_ramp_init() which should have been removed in
openbsc commit ebc1e39d919f5f919cb176ee9c6cbbccc8d620b1

Change-Id: Iadd25016e6478a9dc5da1db42e6192ce0f5cc746
Related: OS2591

1 files changed, 6 insertions, 9 deletions

diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c
index 6147257c4..120955b53 100644
--- a/openbsc/src/libbsc/bsc_init.c
+++ b/openbsc/src/libbsc/bsc_init.c
@@ -311,19 +311,16 @@ static void bootstrap_rsl(struct gsm_bts_trx *trx)
 		trx->bts->location_area_code,
 		trx->bts->cell_identity, trx->bts->bsic);
 
-	/*
-	 * Re-initialize ACC ramping to ensure ACCs are barred/allowed
-	 * according to our current VTY configuration.
-	 */
-	acc_ramp_init(&trx->bts->acc_ramp, acc_ramp_is_enabled(&trx->bts->acc_ramp), trx->bts);
-
 	if (trx->bts->type == GSM_BTS_TYPE_NOKIA_SITE) {
 		rsl_nokia_si_begin(trx);
 	}
 
-	/* Configure ACC ramping before sending system information to BTS. */
-	if (acc_ramp_is_enabled(&trx->bts->acc_ramp))
-		acc_ramp_start(&trx->bts->acc_ramp);
+	/*
+	 * Trigger ACC ramping before sending system information to BTS.
+	 * This ensures that RACH control in system information is configured correctly.
+	 */
+	acc_ramp_trigger(&trx->bts->acc_ramp);
+
 	gsm_bts_trx_set_system_infos(trx);
 
 	if (trx->bts->type == GSM_BTS_TYPE_NOKIA_SITE) {