2020-09-15 17:45:08

by Abhishek Pandit-Subedi

[permalink] [raw]
Subject: [Bluez PATCH v5 4/4] 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).
---

Changes in v5: None
Changes in v4:
- Set reconnect timer in disconnect if resume events aren't supported
- Only set reconnect timer if adapter matches current notification
- Refactor changes in src/adapter to its own commit
- Refactor enabling A2DP_SINK_UUID into its own commit

Changes in v3:
- Refactored resume notification to use btd_adapter_driver
- Renamed ReconnectAudioDelay to ResumeDelay and set default to 2
- Added A2DP_SINK_UUID to default reconnect list

Changes in v2:
- Refactored to use policy instead of connecting directly in adapter

plugins/policy.c | 84 ++++++++++++++++++++++++++++++++++++++++--------
src/main.c | 1 +
src/main.conf | 9 ++++++
3 files changed, 81 insertions(+), 13 deletions(-)

diff --git a/plugins/policy.c b/plugins/policy.c
index c18ca8d1f..6bd389518 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);
@@ -744,10 +754,14 @@ static void reconnect_set_timer(struct reconnect_data *reconnect)
static void disconnect_cb(struct btd_device *dev, uint8_t reason)
{
struct reconnect_data *reconnect;
+ struct btd_service *service;
+ struct policy_data *data;

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 +770,47 @@ 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 +838,15 @@ 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 +854,7 @@ 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 +908,20 @@ 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 +942,7 @@ 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,
diff --git a/src/main.c b/src/main.c
index b37c32948..038f867b5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -131,6 +131,7 @@ static const char *policy_options[] = {
"ReconnectAttempts",
"ReconnectIntervals",
"AutoEnable",
+ "ResumeDelay",
NULL
};

diff --git a/src/main.conf b/src/main.conf
index e1d77cc47..9f882e65a 100644
--- a/src/main.conf
+++ b/src/main.conf
@@ -202,3 +202,12 @@
# This includes adapters present on start as well as adapters that are plugged
# in later on. Defaults to 'false'.
#AutoEnable=false
+
+# Audio devices that were disconnected due to suspend will be reconnected on
+# resume. ResumeDelay determines the delay between when the controller
+# resumes from suspend and a connection attempt is made. A longer delay is
+# better for better co-existence with Wi-Fi.
+# The value is in seconds.
+# Default: 2
+#ResumeDelay = 2
+
--
2.28.0.618.gf4bc123cb7-goog