policy: Reconnect audio on controller resume

During system suspend, all peer devices are disconnected. On resume, HID
devices will reconnect but audio devices stay disconnected. As a quality
of life improvement, mark audio devices that were disconnected due to
suspend and attempt to reconnect them when the controller resumes (after
a delay for better co-existence with Wi-Fi).

1 files changed, 68 insertions, 13 deletions

diff --git a/plugins/policy.c b/plugins/policy.c
index c18ca8d1f..655842942 100644
--- a/plugins/policy.c
+++ b/plugins/policy.c
@@ -62,6 +62,7 @@ struct reconnect_data {
 	guint timer;
 	bool active;
 	unsigned int attempt;
+	bool on_resume;
 };
 
 static const char *default_reconnect[] = {
@@ -76,6 +77,9 @@ static const int default_intervals[] = { 1, 2, 4, 8, 16, 32, 64 };
 static int *reconnect_intervals = NULL;
 static size_t reconnect_intervals_len = 0;
 
+static const int default_resume_delay = 2;
+static int resume_delay;
+
 static GSList *reconnects = NULL;
 
 static unsigned int service_id = 0;
@@ -712,6 +716,9 @@ static gboolean reconnect_timeout(gpointer data)
 	/* Mark the GSource as invalid */
 	reconnect->timer = 0;
 
+	/* Mark any reconnect on resume as handled */
+	reconnect->on_resume = false;
+
 	err = btd_device_connect_services(reconnect->dev, reconnect->services);
 	if (err < 0) {
 		error("Reconnecting services failed: %s (%d)",
@@ -725,14 +732,17 @@ static gboolean reconnect_timeout(gpointer data)
 	return FALSE;
 }
 
-static void reconnect_set_timer(struct reconnect_data *reconnect)
+static void reconnect_set_timer(struct reconnect_data *reconnect, int timeout)
 {
-	static int timeout = 0;
+	static int interval_timeout = 0;
 
 	reconnect->active = true;
 
 	if (reconnect->attempt < reconnect_intervals_len)
-		timeout = reconnect_intervals[reconnect->attempt];
+		interval_timeout = reconnect_intervals[reconnect->attempt];
+
+	if (timeout < 0)
+		timeout = interval_timeout;
 
 	DBG("attempt %u/%zu %d seconds", reconnect->attempt + 1,
 						reconnect_attempts, timeout);
@@ -747,7 +757,9 @@ static void disconnect_cb(struct btd_device *dev, uint8_t reason)
 
 	DBG("reason %u", reason);
 
-	if (reason != MGMT_DEV_DISCONN_TIMEOUT)
+	/* Only attempt reconnect for the following reasons */
+	if (reason != MGMT_DEV_DISCONN_TIMEOUT &&
+	    reason != MGMT_DEV_DISCONN_LOCAL_HOST_SUSPEND)
 		return;
 
 	reconnect = reconnect_find(dev);
@@ -756,10 +768,46 @@ static void disconnect_cb(struct btd_device *dev, uint8_t reason)
 
 	reconnect_reset(reconnect);
 
-	DBG("Device %s identified for auto-reconnection",
-							device_get_path(dev));
+	DBG("Device %s identified for auto-reconnection", device_get_path(dev));
+
+	switch (reason) {
+	case MGMT_DEV_DISCONN_LOCAL_HOST_SUSPEND:
+		if (btd_device_get_service(dev, A2DP_SINK_UUID)) {
+			DBG("%s configured to reconnect on resume",
+				device_get_path(dev));
 
-	reconnect_set_timer(reconnect);
+			reconnect->on_resume = true;
+
+			/* If the kernel supports resume events, it is
+			 * preferable to set the reconnect timer there as it is
+			 * a more predictable delay.
+			 */
+			if (!has_kernel_features(KERNEL_HAS_RESUME_EVT))
+				reconnect_set_timer(reconnect, resume_delay);
+		}
+		break;
+	case MGMT_DEV_DISCONN_TIMEOUT:
+		reconnect_set_timer(reconnect, -1);
+		break;
+	default:
+		DBG("Developer error. Reason = %d", reason);
+		break;
+	}
+}
+
+static void policy_adapter_resume(struct btd_adapter *adapter)
+{
+	GSList *l;
+
+	/* Check if devices on this adapter need to be reconnected on resume */
+	for (l = reconnects; l; l = g_slist_next(l)) {
+		struct reconnect_data *reconnect = l->data;
+
+		if (reconnect->on_resume &&
+		    device_get_adapter(reconnect->dev) == adapter) {
+			reconnect_set_timer(reconnect, resume_delay);
+		}
+	}
 }
 
 static void conn_fail_cb(struct btd_device *dev, uint8_t status)
@@ -787,14 +835,15 @@ static void conn_fail_cb(struct btd_device *dev, uint8_t status)
 		return;
 	}
 
-	reconnect_set_timer(reconnect);
+	reconnect_set_timer(reconnect, -1);
 }
 
 static int policy_adapter_probe(struct btd_adapter *adapter)
 {
 	DBG("");
 
-	btd_adapter_restore_powered(adapter);
+	if (auto_enable)
+		btd_adapter_restore_powered(adapter);
 
 	return 0;
 }
@@ -802,6 +851,7 @@ static int policy_adapter_probe(struct btd_adapter *adapter)
 static struct btd_adapter_driver policy_driver = {
 	.name	= "policy",
 	.probe	= policy_adapter_probe,
+	.resume = policy_adapter_resume,
 };
 
 static int policy_init(void)
@@ -855,14 +905,20 @@ static int policy_init(void)
 	auto_enable = g_key_file_get_boolean(conf, "Policy", "AutoEnable",
 									NULL);
 
+	resume_delay = g_key_file_get_integer(
+			conf, "Policy", "ResumeDelay", &gerr);
+
+	if (gerr) {
+		g_clear_error(&gerr);
+		resume_delay = default_resume_delay;
+	}
 done:
 	if (reconnect_uuids && reconnect_uuids[0] && reconnect_attempts) {
 		btd_add_disconnect_cb(disconnect_cb);
 		btd_add_conn_fail_cb(conn_fail_cb);
 	}
 
-	if (auto_enable)
-		btd_register_adapter_driver(&policy_driver);
+	btd_register_adapter_driver(&policy_driver);
 
 	return 0;
 }
@@ -883,8 +939,7 @@ static void policy_exit(void)
 
 	btd_service_remove_state_cb(service_id);
 
-	if (auto_enable)
-		btd_unregister_adapter_driver(&policy_driver);
+	btd_unregister_adapter_driver(&policy_driver);
 }
 
 BLUETOOTH_PLUGIN_DEFINE(policy, VERSION, BLUETOOTH_PLUGIN_PRIORITY_DEFAULT,