bts_model: Allow TS connect to be processed asynchronously

This commit doesn't change internal logic of any model, only the API to
be able to return result of connect TS asyncrhonously since some models
(like osmo-bts-trx) require some time to process the result. This way
PDCH ACT/DEACT (N)ACK can be sent once the result of this long process
is known. For instance, nowadays in osmo-bts-trx we PDCH (DE)ACT ACK
before getting the result from SETSLOT on the TRX iface.

With this new API, bts_model_ts_connect doesn't return any value
synchronously. Instead, it is expected to always end up calling
cb_ts_connected with the return code from the TS activation process. 0
is considered a successs, while any other value is considered an error.

Change-Id: Ie073a4397dd2f1a691968d12b15b8b42f1e1b0cf

1 files changed, 22 insertions, 10 deletions

diff --git a/src/common/rsl.c b/src/common/rsl.c
index 9b0de7cf..507e8aaf 100644
--- a/src/common/rsl.c
+++ b/src/common/rsl.c
@@ -2157,7 +2157,7 @@ static int rsl_tx_dyn_pdch_nack(struct gsm_lchan *lchan, bool pdch_act,
  * 1. call bts_model_ts_disconnect() to disconnect TCH/F;
  * 2. cb_ts_disconnected() is called when done;
  * 3. call bts_model_ts_connect() to connect as PDTCH;
- * 4. cb_ts_connected() is called when done;
+ * 4. cb_ts_connected(rc) is called when done;
  * 5. instruct the PCU to enable PDTCH;
  * 6. the PCU will call back with an activation request;
  * 7. l1sap_info_act_cnf() will call ipacc_dyn_pdch_complete() when SAPI
@@ -2171,7 +2171,7 @@ static int rsl_tx_dyn_pdch_nack(struct gsm_lchan *lchan, bool pdch_act,
  *    deactivations are done;
  * 4. cb_ts_disconnected() is called when done;
  * 5. call bts_model_ts_connect() to connect as TCH/F;
- * 6. cb_ts_connected() is called when done;
+ * 6. cb_ts_connected(rc) is called when done;
  * 7. directly call ipacc_dyn_pdch_complete(), since no further action required
  *    for TCH/F;
  * 8. send a PDCH DEACT ACK.
@@ -2276,7 +2276,8 @@ static void ipacc_dyn_pdch_ts_disconnected(struct gsm_bts_trx_ts *ts)
 	if (rc)
 		goto error_nack;
 
-	rc = bts_model_ts_connect(ts, as_pchan);
+	bts_model_ts_connect(ts, as_pchan);
+	return;
 
 error_nack:
 	/* Error? then NACK right now. */
@@ -2322,9 +2323,14 @@ void cb_ts_disconnected(struct gsm_bts_trx_ts *ts)
 	}
 }
 
-static void ipacc_dyn_pdch_ts_connected(struct gsm_bts_trx_ts *ts)
+static void ipacc_dyn_pdch_ts_connected(struct gsm_bts_trx_ts *ts, int rc)
 {
-	int rc;
+	if (rc) {
+		LOGP(DRSL, LOGL_NOTICE, "%s PDCH ACT IPA operation failed (%d) in bts model\n",
+		     gsm_lchan_name(ts->lchan), rc);
+		ipacc_dyn_pdch_complete(ts, rc);
+		return;
+	}
 
 	if (ts->flags & TS_F_PDCH_DEACT_PENDING) {
 		if (ts->lchan[0].type != GSM_LCHAN_TCH_F)
@@ -2373,12 +2379,18 @@ static void ipacc_dyn_pdch_ts_connected(struct gsm_bts_trx_ts *ts)
 	}
 }
 
-static void osmo_dyn_ts_connected(struct gsm_bts_trx_ts *ts)
+static void osmo_dyn_ts_connected(struct gsm_bts_trx_ts *ts, int rc)
 {
-	int rc;
 	struct msgb *msg = ts->dyn.pending_chan_activ;
 	ts->dyn.pending_chan_activ = NULL;
 
+	if (rc) {
+		LOGP(DRSL, LOGL_NOTICE, "%s PDCH ACT OSMO operation failed (%d) in bts model\n",
+		     gsm_lchan_name(ts->lchan), rc);
+		ipacc_dyn_pdch_complete(ts, rc);
+		return;
+	}
+
 	if (!msg) {
 		LOGP(DRSL, LOGL_ERROR,
 		     "%s TS re-connected, but no chan activ msg pending\n",
@@ -2395,15 +2407,15 @@ static void osmo_dyn_ts_connected(struct gsm_bts_trx_ts *ts)
 		msgb_free(msg);
 }
 
-void cb_ts_connected(struct gsm_bts_trx_ts *ts)
+void cb_ts_connected(struct gsm_bts_trx_ts *ts, int rc)
 {
 	OSMO_ASSERT(ts);
 
 	switch (ts->pchan) {
 	case GSM_PCHAN_TCH_F_PDCH:
-		return ipacc_dyn_pdch_ts_connected(ts);
+		return ipacc_dyn_pdch_ts_connected(ts, rc);
 	case GSM_PCHAN_TCH_F_TCH_H_PDCH:
-		return osmo_dyn_ts_connected(ts);
+		return osmo_dyn_ts_connected(ts, rc);
 	default:
 		return;
 	}