ASCI: Repeat notification after assigning MS to VGCS/VBS channel

The assignment is repeated because the calling subscriber may not
receive the notification on the DCCH, during handover process. After the
assignment is complete, the calling subscriber will receive
notification.

This cannot be done automatically by the BTS, because the BTS has no
relation between the notifications and the channels.

The notification is required, so that the MS knows the channel to listen
to when leaving the uplink the first time. If no notification is
received, the MS will abort the call.

Change-Id: Ife568b8c2756be332c0b8de21111f66f6e537c4d

src/osmo-bsc/vgcs_fsm.c

@@ -795,6 +795,8 @@ static void vgcs_chan_fsm_active_blocked(struct osmo_fsm_inst *fi, uint32_t even
 		/* Report talker detection to call state machine. */
 		if (conn->vgcs_chan.call)
 			osmo_fsm_inst_dispatch(conn->vgcs_chan.call->vgcs_call.fi, VGCS_EV_CALLING_ASSIGNED, conn);
+		/* Repeat notification for the MS that has been assigned. */
+		rsl_notification_cmd(conn->lchan->ts->trx->bts, conn->lchan, &conn->vgcs_chan.gc_ie, NULL);
 		break;
 	case VGCS_EV_CLEANUP:
 		LOG_CHAN(conn, LOGL_DEBUG, "SCCP connection clearing.\n");