[PATCH BlueZ] adapter: add BCAA UUID also when seen device is not discoverable

[Pauli Virtanen <pav@iki.fi>]

BAP v1.0.2 Sec 6.4 specifies Broadcast discovery uses observation
procedure (Core Vol 3 Part C Sec 9.1.2) which makes no reference to
device discoverability state.

However, if remote device does:

1. Send Advertising Data for some other UUID with General Discoverable
2. Send Advertising Data for BCAA UUID with no flags

then adapter.c:btd_adapter_device_found() creates device in step 1. but
in step 2. it ignores the BCAA UUID since the device exists but is not
discoverable; the monitoring=true special case applies only for
first-seen devices.  Consequently bap plugin fails to pick up the BCAA
stream.

This sequence was observed to be produced by BlueZ + btvirt.

Fix by monitoring also previously existing but currently non-connectable
devices with BCAA UUID.

Link: https://gitlab.freedesktop.org/pipewire/pipewire/-/merge_requests/2812#note_3467783
Log:
--------------------------
@ MGMT Event: Device Found (0x0012) plen 17
        LE Address: 00:AA:01:00:00:42 (Intel Corporation)
        RSSI: invalid (0x7f)
        Flags: 0x00000000
        Data length: 3
        Data[3]:
        02 01 06                                         ...
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
...
@ MGMT Event: Device Found (0x0012) plen 39
        LE Address: 00:AA:01:00:00:42 (Intel Corporation)
        RSSI: invalid (0x7f)
        Flags: 0x00000004
          Not Connectable
        Data length: 25
        Data[25]:
        06 16 52 18 56 db 55 03 03 4e 18 0d 16 4e 18 00  ..R.V.U..N...N..
        ff 0f 0f 00 04 03 01 01 00                       .........
        Service Data: Broadcast Audio Announcement (0x1852)
        Broadcast ID: 5626710 (0x55db56)
        16-bit Service UUIDs (complete): 1 entry
          Audio Stream Control (0x184e)
        Service Data: Audio Stream Control (0x184e)
          Data[10]:
        00 ff 0f 0f 00 04 03 01 01 00
--------------------------
---
 src/adapter.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/adapter.c b/src/adapter.c
index 6df66b3e0..20f7c3e03 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -7360,6 +7360,14 @@ void btd_adapter_device_found(struct btd_adapter *adapter,
 	discoverable = device_is_discoverable(adapter, &eir_data, addr,
 						bdaddr_type, &auto_connect);
 
+	/* Monitor Devices advertising Broadcast Announcements if the
+	 * adapter is capable of synchronizing to it.
+	 */
+	if (eir_get_service_data(&eir_data, BCAA_SERVICE_UUID) &&
+					btd_adapter_has_settings(adapter,
+					MGMT_SETTING_ISO_SYNC_RECEIVER))
+		monitoring = true;
+
 	dev = btd_adapter_find_device(adapter, bdaddr, bdaddr_type);
 	if (!dev) {
 		/* In case of being just a scan response don't attempt to create
@@ -7370,14 +7378,6 @@ void btd_adapter_device_found(struct btd_adapter *adapter,
 			return;
 		}
 
-		/* Monitor Devices advertising Broadcast Announcements if the
-		 * adapter is capable of synchronizing to it.
-		 */
-		if (eir_get_service_data(&eir_data, BCAA_SERVICE_UUID) &&
-				btd_adapter_has_settings(adapter,
-				MGMT_SETTING_ISO_SYNC_RECEIVER))
-			monitoring = true;
-
 		/* If ISO  Socket is enabled, monitor Devices advertising RSI
 		 * since those can be coordinated sets not marked as visible but
 		 * their object are needed.
-- 
2.54.0