emulator: Improve SLC establishment logic

src/emulator.c

@@ -636,7 +636,8 @@ done:
 
 		g_at_server_send_final(server, G_AT_SERVER_RESULT_OK);
 
-		em->slc = TRUE;
+		__ofono_emulator_slc_condition(em,
+					OFONO_EMULATOR_SLC_CONDITION_CMER);
 		break;
 	}
 
@@ -1266,3 +1267,31 @@ void __ofono_emulator_set_indicator_forced(struct ofono_emulator *em,
 			ind->deferred = TRUE;
 	}
 }
+
+void __ofono_emulator_slc_condition(struct ofono_emulator *em,
+					enum ofono_emulator_slc_condition cond)
+{
+	if (em->slc == TRUE)
+		return;
+
+	switch (cond) {
+	case OFONO_EMULATOR_SLC_CONDITION_CMER:
+		if ((em->r_features & HFP_HF_FEATURE_3WAY) &&
+				(em->l_features & HFP_AG_FEATURE_3WAY))
+			return;
+		/* Fall Through */
+
+	case OFONO_EMULATOR_SLC_CONDITION_CHLD:
+		if ((em->r_features & HFP_HF_FEATURE_HF_INDICATORS) &&
+				(em->l_features & HFP_HF_FEATURE_HF_INDICATORS))
+			return;
+		/* Fall Through */
+
+	case OFONO_EMULATOR_SLC_CONDITION_BIND:
+		ofono_info("SLC reached");
+		em->slc = TRUE;
+
+	default:
+		break;
+	}
+}

src/ofono.h

@@ -505,8 +505,17 @@ void __ofono_gprs_provision_free_settings(
 				int count);
 
 #include <ofono/emulator.h>
+
+enum ofono_emulator_slc_condition {
+	OFONO_EMULATOR_SLC_CONDITION_CMER,
+	OFONO_EMULATOR_SLC_CONDITION_CHLD,
+	OFONO_EMULATOR_SLC_CONDITION_BIND,
+};
+
 void __ofono_emulator_set_indicator_forced(struct ofono_emulator *em,
 						const char *name, int value);
+void __ofono_emulator_slc_condition(struct ofono_emulator *em,
+					enum ofono_emulator_slc_condition cond);
 
 #include <ofono/gnss.h>
 #include <ofono/cdma-sms.h>

src/voicecall.c

@@ -3304,6 +3304,10 @@ static void emulator_chld_cb(struct ofono_emulator *em,
 
 		ofono_emulator_send_info(em, buf, TRUE);
 		result.type = OFONO_ERROR_TYPE_NO_ERROR;
+
+		__ofono_emulator_slc_condition(em,
+					OFONO_EMULATOR_SLC_CONDITION_CHLD);
+
 		break;
 
 	case OFONO_EMULATOR_REQUEST_TYPE_QUERY: