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Add a DisableDiscoveryOnConnect boolean option to the [General] section of main.conf. When enabled and an active connection exists, the option suppresses adding devices to the kernel auto-connect list in adapter_auto_connect_add() on kernels supporting KERNEL_CONN_CONTROL, and gates trigger_passive_scanning() on older kernels. The option defaults to false to preserve existing behavior. Signed-off-by: StefanCondorache --- src/adapter.c | 24 ++++++++++++++++++++++++ src/btd.h | 2 ++ src/main.c | 4 ++++ src/main.conf | 6 ++++++ 4 files changed, 36 insertions(+) diff --git a/src/adapter.c b/src/adapter.c index 6df66b3e0..4a18adfe0 100644 --- a/src/adapter.c +++ b/src/adapter.c @@ -1594,6 +1594,18 @@ static void trigger_passive_scanning(struct btd_adapter *adapter) if (!adapter->connect_list) return; + /* + * If the user has enabled DisableDiscoveryOnConnect, suppress + * passive scanning whenever there is at least one active connection. + * This prevents antenna multiplexing conflicts on combo chips where + * Wi-Fi and Bluetooth share the same 2.4 GHz radio, which causes + * audio drops and Wi-Fi packet loss during background scans. + */ + if (btd_opts.disable_discovery_on_connect && adapter->connections) { + DBG("suppress passive scan: active connection present"); + return; + } + adapter->passive_scan_timeout = timeout_add_seconds(CONN_SCAN_TIMEOUT, passive_scanning_timeout, adapter, NULL); @@ -5717,6 +5729,18 @@ void adapter_auto_connect_add(struct btd_adapter *adapter, return; } + /* + * If DisableDiscoveryOnConnect is enabled, suppress adding devices + * to the kernel auto-connect list while an active connection exists. + * On combo chips (shared Wi-Fi/Bluetooth antenna), the kernel's + * background scanning for auto-connect devices competes with active + * connections, causing audio drops and Wi-Fi packet loss. + */ + if (btd_opts.disable_discovery_on_connect && adapter->connections) { + DBG("suppress kernel auto-connect: active connection present"); + return; + } + bdaddr = device_get_address(device); bdaddr_type = btd_device_get_bdaddr_type(device); diff --git a/src/btd.h b/src/btd.h index c84a600d1..07c4d85ba 100644 --- a/src/btd.h +++ b/src/btd.h @@ -144,6 +144,8 @@ struct btd_opts { bool experimental; bool testing; bool filter_discoverable; + bool disable_discovery_on_connect; + struct queue *kernel; uint16_t did_source; diff --git a/src/main.c b/src/main.c index 818f7c06e..d7ddf5643 100644 --- a/src/main.c +++ b/src/main.c @@ -92,6 +92,7 @@ static const char *supported_options[] = { "KernelExperimental", "RemoteNameRequestRetryDelay", "FilterDiscoverable", + "DisableDiscoveryOnConnect", NULL }; @@ -1072,6 +1073,8 @@ static void parse_general(GKeyFile *config) 0, UINT32_MAX); parse_config_bool(config, "General", "FilterDiscoverable", &btd_opts.filter_discoverable); + parse_config_bool(config, "General", "DisableDiscoveryOnConnect", + &btd_opts.disable_discovery_on_connect); } static void parse_gatt_cache(GKeyFile *config) @@ -1283,6 +1286,7 @@ static void init_defaults(void) btd_opts.name_request_retry_delay = DEFAULT_NAME_REQUEST_RETRY_DELAY; btd_opts.secure_conn = SC_ON; btd_opts.filter_discoverable = true; + btd_opts.disable_discovery_on_connect = false; btd_opts.defaults.num_entries = 0; btd_opts.defaults.br.page_scan_type = 0xFFFF; diff --git a/src/main.conf b/src/main.conf index d31dd1b8f..22507c465 100644 --- a/src/main.conf +++ b/src/main.conf @@ -157,6 +157,12 @@ # some stacks) or when testing bad/unintended behavior. #FilterDiscoverable = true +# Disables background LE passive scanning when an active connection is +# established. Recommended for combo chips (shared Wi-Fi/Bluetooth antenna) +# to prevent audio stuttering and packet loss caused by antenna multiplexing. +# Defaults to false. +#DisableDiscoveryOnConnect = false + [BR] # The following values are used to load default adapter parameters for BR/EDR. # BlueZ loads the values into the kernel before the adapter is powered if the -- 2.53.0