Hi,
I am seeing the following behaviour with an android device running the
8723au chipset with bluez + backports + btusb.c (new branch).
Step 1:
1: enable BT via settings UI
2: open BLE scanner app
3: app finds all BLE devices
Step 2:
4: close BLE scanner app
5: open BLE scanner app
6: app cannot find any BLE device
- Szymon has suggested it is related to duplicate filtering and may be
handled at the driver or chipset firmware level.
- I found this post which might provide some useful background info.
http://stackoverflow.com/questions/19502853/android-4-3-ble-filtering-behaviour-of-startlescan
- My question is can I do anything at the driver/kernel/bluez level so
that BLE devices always show up?
LOGS
- I see the following output in logcat:
Step 1:
10-24 07:06:27.450 D/TAG (13289): ~ Starting Scan
10-24 07:06:27.450 D/BluetoothAdapter(13289): startLeScan(): null
10-24 07:06:27.450 D/BtGatt.GattService(13351): registerClient() -
UUID=3ed977cb-dddb-4518-af26-eb41adb97c38
10-24 07:06:27.450 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:handle_client_register()
10-24 07:06:27.460 D/BtGatt.GattService(13351): onClientRegistered() -
UUID=3ed977cb-dddb-4518-af26-eb41adb97c38, clientIf=1
10-24 07:06:27.460 D/BluetoothAdapter(13289): onClientRegistered() -
status=0 clientIf=1
10-24 07:06:27.460 D/BtGatt.GattService(13351): startScan() - queue=0
10-24 07:06:27.460 D/BtGatt.GattService(13351): startScan() - adding client=1
10-24 07:06:27.470 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() new state 1
10-24 07:06:27.470 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-24 07:06:27.470 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-24 07:06:27.480 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
10-24 07:06:27.510 W/InputMethodManagerService( 1612): Window already
focused, ignoring focus gain of:
com.android.internal.view.IInputMethodClient$Stub$Proxy@41a51080
attribute=null, token = android.os.BinderProxy@41aa49c0
10-24 07:06:27.530 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_device_found_event()
hci0 addr BC:6A:29:AB:2C:AA, rssi -36 flags 0x0000 eir_len 25
10-24 07:06:27.530 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:le_device_found_handler() LE
Device found: BC:6A:29:AB:2C:AA, rssi: -36, adv_data: 1
10-24 07:06:27.540 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:handle_device_found()
10-24 07:06:27.550 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[0]: type=BT_PROPERTY_BDADDR len=6 val=bc:6a:29:ab:2c:aa
10-24 07:06:27.550 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[1]: type=BT_PROPERTY_TYPE_OF_DEVICE len=4 val=BT_DEVICE_DEVTYPE_BLE
10-24 07:06:27.550 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[2]: type=BT_PROPERTY_REMOTE_RSSI len=4 val=220
10-24 07:06:27.550 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[3]: type=BT_PROPERTY_BDNAME len=17 val=BC:6A:29:AB:2C:AA
10-24 07:06:27.580 D/BtGatt.GattService(13351): onScanResult() -
address=BC:6A:29:AB:2C:AA, rssi=-36
10-24 07:06:27.580 D/BluetoothAdapter(13289): onScanResult() -
Device=BC:6A:29:AB:2C:AA RSSI=-36
10-24 07:06:27.690 D/BluetoothEventManager( 1767): DeviceFoundHandler
created new CachedBluetoothDevice: BC:6A:29:AB:2C:AA
10-24 07:06:27.730 D/android.widget.GridLayout(13289): horizontal
constraints: x2-x0>=376, x2-x1<=187, x1-x0<=81 are inconsistent;
permanently removing: x2-x1<=187.
10-24 07:06:37.720 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_device_found_event()
hci0 addr BC:6A:29:AB:2D:17, rssi -48 flags 0x0000 eir_len 25
10-24 07:06:37.720 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:le_device_found_handler() LE
Device found: BC:6A:29:AB:2D:17, rssi: -48, adv_data: 1
10-24 07:06:37.730 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 0
10-24 07:06:37.730 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:handle_device_found()
10-24 07:06:37.730 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 0 6
10-24 07:06:37.730 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-24 07:06:37.740 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[0]: type=BT_PROPERTY_BDADDR len=6 val=bc:6a:29:ab:2d:17
10-24 07:06:37.740 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[1]: type=BT_PROPERTY_TYPE_OF_DEVICE len=4 val=BT_DEVICE_DEVTYPE_BLE
10-24 07:06:37.740 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[2]: type=BT_PROPERTY_REMOTE_RSSI len=4 val=208
10-24 07:06:37.740 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-24 07:06:37.740 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
10-24 07:06:37.750 D/BlueZ (13351):
external/bluetooth/bluez/android/hal-bluetooth.c:device_props_to_hal()
prop[3]: type=BT_PROPERTY_BDNAME len=17 val=BC:6A:29:AB:2D:17
10-24 07:06:37.770 D/BtGatt.GattService(13351): onScanResult() -
address=BC:6A:29:AB:2D:17, rssi=-48
10-24 07:06:37.780 D/BluetoothAdapter(13289): onScanResult() -
Device=BC:6A:29:AB:2D:17 RSSI=-48
10-24 07:06:37.870 D/android.widget.GridLayout(13289): horizontal
constraints: x2-x0>=376, x2-x1<=187, x1-x0<=81 are inconsistent;
permanently removing: x2-x1<=187.
10-24 07:06:37.870 D/BluetoothEventManager( 1767): DeviceFoundHandler
created new CachedBluetoothDevice: BC:6A:29:AB:2D:17
Step 2:
10-24 07:15:09.150 D/TAG (13289): ~ Starting Scan
10-24 07:15:09.150 D/BluetoothAdapter(13289): startLeScan(): null
10-24 07:15:09.170 D/BtGatt.GattService(13351): registerClient() -
UUID=e423968e-1bfe-4822-a62b-83804fb6998d
10-24 07:15:09.170 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:handle_client_register()
10-24 07:15:09.170 D/BtGatt.GattService(13351): onClientRegistered() -
UUID=e423968e-1bfe-4822-a62b-83804fb6998d, clientIf=2
10-24 07:15:09.170 D/BluetoothAdapter(13289): onClientRegistered() -
status=0 clientIf=2
10-24 07:15:09.170 D/BtGatt.GattService(13351): startScan() - queue=0
10-24 07:15:09.180 D/BtGatt.GattService(13351): startScan() - adding client=2
10-24 07:15:09.180 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() new state 1
10-24 07:15:09.180 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-24 07:15:09.190 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-24 07:15:09.190 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
10-24 07:15:09.250 W/InputMethodManagerService( 1612): Window already
focused, ignoring focus gain of:
com.android.internal.view.IInputMethodClient$Stub$Proxy@41b85ab8
attribute=null, token = android.os.BinderProxy@41afac00
10-24 07:15:19.440 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 0
10-24 07:15:19.440 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 0 6
10-24 07:15:19.450 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-24 07:15:19.460 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-24 07:15:19.460 I/bluetoothd(13365): bluetoothd[13366]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
- I see the following output in btmon:
Step 1:
# btmon
Bluetooth monitor ver 5.23
= New Index: CC:D2:9C:73:CB:45 (BR/EDR,USB,hci0) [hci0]
0.921673
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
6.885250
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
6.886777
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
6.891384
Address: 33:31:38:D9:1B:2E (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
6.892774
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
6.892944
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
6.894777
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
6.895268
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
6.896768
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
17.165233
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
17.166804
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
17.172436
Address: 30:D0:1B:39:11:67 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
17.173779
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
17.173957
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
17.175784
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
17.175969
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
17.182437
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
27.445182
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
27.446769
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
27.452355
Address: 1F:D8:B6:3C:C6:59 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
27.453758
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
27.453928
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
27.461737
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
27.462099
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
27.464075
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
37.725179
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
37.726766
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
37.732082
Address: 26:B7:AE:E6:75:57 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
37.733782
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
37.734090
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
37.735758
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
37.735871
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
37.736753
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
48.005204
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
48.006786
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
48.016702
Address: 06:D6:55:3D:29:5F (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
48.017777
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
48.018674
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
48.019771
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
48.019967
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
48.021775
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
58.290259
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
58.291852
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
58.297162
Address: 06:E6:71:FF:BA:41 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
58.298778
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
58.299040
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
58.300779
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
58.301042
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
58.302784
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
68.565182
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
68.566772
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
68.573095
Address: 25:42:7A:0D:BF:7D (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
68.574788
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
68.575193
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
68.576785
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
68.577027
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
68.584697
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
78.845191
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
78.846780
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
78.853717
Address: 3A:B8:26:AA:9B:12 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
78.854825
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
78.856067
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
78.857777
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
78.859335
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
78.864484
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
/// Step 2:
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
99.375289
Address: 25:61:0F:37:30:99 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
99.378071
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
99.379701
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
99.380778
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
99.380939
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
99.382768
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
109.645175
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
109.646778
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x00 (6)
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 [hci0]
109.652523
Address: 3F:4D:C3:01:6A:72 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
109.653782
LE Set Random Address (0x08|0x0005) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0]
109.654052
Type: Active (0x01)
Interval: 11.250 msec (0x0012)
Window: 11.250 msec (0x0012)
Own address type: Random (0x01)
Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
109.655774
LE Set Scan Parameters (0x08|0x000b) ncmd 2
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0]
109.656344
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 [hci0]
109.657769
LE Set Scan Enable (0x08|0x000c) ncmd 2
Status: Success (0x00)
@ Discovering: 0x01 (6)
--
Patrick Shirkey
Boost Hardware Ltd
On Wed, October 29, 2014 4:20 am, Marcel Holtmann wrote:
> Hi Patrick,
>
>> I am seeing the following behaviour with an android device running the
>> 8723au chipset with bluez + backports + btusb.c (new branch).
>>
>> Step 1:
>>
>> 1: enable BT via settings UI
>> 2: open BLE scanner app
>> 3: app finds all BLE devices
>>
>> Step 2:
>>
>> 4: close BLE scanner app
>> 5: open BLE scanner app
>> 6: app cannot find any BLE device
>>
>>
>> - Szymon has suggested it is related to duplicate filtering and may be
>> handled at the driver or chipset firmware level.
>>
>> - I found this post which might provide some useful background info.
>>
>> http://stackoverflow.com/questions/19502853/android-4-3-ble-filtering-behaviour-of-startlescan
>>
>> - My question is can I do anything at the driver/kernel/bluez level so
>> that BLE devices always show up?
>
> so we are always using the duplicate filtering of the controller. Not
> using it will cause an overflow of advertising reports in a busy
> environment.
>
> The difference between certain manufactures is that some filter strictly
> only on address, other filter on address + RSSI. Meaning that if the RSSI
> changes you get another event. What I know is that Broadcom is in the
> first camp and CSR/TI are in the second camp.
>
> This means that if you care about devices found on a constant basis and
> depend on the RSSI changing, you need to stop and restart the LE scan for
> at least Broadcom based controllers. I have no idea in what camp the
> Realtek one falls since I yet have to get one of these.
>
I have an app here that is designed to start a new scan via the android
API every time it checks for available BLE devices. The app runs well on
other devices with different chipsets. The results on the 8723au might be
useful information. I can see BLE devices have been found in the settings
UI but the test app is not getting anything useful from the Android layer.
Example output:
10-28 13:50:46.270 D/BluetoothAdapter(25700): startLeScan(): null
10-28 13:50:46.270 D/BtGatt.GattService(14120): registerClient() -
UUID=623b34f6-592b-4d61-9c7f-d6c124f470d1
10-28 13:50:46.270 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_register()
10-28 13:50:46.270 D/BtGatt.GattService(14120): onClientRegistered() -
UUID=623b34f6-592b-4d61-9c7f-d6c124f470d1, clientIf=94
10-28 13:50:46.270 D/BluetoothAdapter(25700): onClientRegistered() -
status=0 clientIf=94
10-28 13:50:46.280 D/BtGatt.GattService(14120): startScan() - queue=0
10-28 13:50:46.280 D/BtGatt.GattService(14120): startScan() - adding
client=94
10-28 13:50:46.280 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() new state 1
10-28 13:50:46.280 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-28 13:50:46.280 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-28 13:50:46.280 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
10-28 13:50:51.290 D/BluetoothAdapter(25700): stopLeScan()
10-28 13:50:51.290 D/BtGatt.GattService(14120): stopScan() - queue=1
10-28 13:50:51.290 D/BtGatt.GattService(14120): stopScan() - queue empty;
stopping scan
10-28 13:50:51.290 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() new state 0
10-28 13:50:51.290 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() Stopping LE
SCAN
10-28 13:50:51.290 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:stop_discovery() type=0x6
10-28 13:50:51.300 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 0
10-28 13:50:51.300 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 0 6
10-28 13:50:51.300 D/BtGatt.GattService(14120): unregisterClient() -
clientIf=94
10-28 13:50:51.300 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_unregister()
10-28 13:50:51.310 D/BluetoothAdapter(25700): startLeScan(): null
10-28 13:50:51.310 D/BtGatt.GattService(14120): registerClient() -
UUID=40001646-6658-4840-bf66-c6ebc5c0c718
10-28 13:50:51.310 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_register()
10-28 13:50:51.320 D/BtGatt.GattService(14120): onClientRegistered() -
UUID=40001646-6658-4840-bf66-c6ebc5c0c718, clientIf=95
10-28 13:50:51.320 D/BluetoothAdapter(25700): onClientRegistered() -
status=0 clientIf=95
10-28 13:50:51.320 D/BtGatt.GattService(14120): startScan() - queue=0
10-28 13:50:51.320 D/BtGatt.GattService(14120): startScan() - adding
client=95
10-28 13:50:51.320 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/gatt.c:handle_client_scan() new state 1
10-28 13:50:51.320 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:start_discovery() type=0x6
10-28 13:50:51.330 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:mgmt_discovering_event() type
6 discovering 1
10-28 13:50:51.330 I/bluetoothd(14150): bluetoothd[14151]:
external/bluetooth/bluez/android/bluetooth.c:check_discovery_state() 6 0
etc...
> On an independent thread we are talking about adding a quirk to our
> internal discovery handling to automatically restart scan for the
> controllers that do the strict filtering based on address only.
>
I'll try to follow the thread but feel free to ping me directly if/when
some code appears.
--
Patrick Shirkey
Boost Hardware Ltd
Hi Patrick,
> I am seeing the following behaviour with an android device running the
> 8723au chipset with bluez + backports + btusb.c (new branch).
>
> Step 1:
>
> 1: enable BT via settings UI
> 2: open BLE scanner app
> 3: app finds all BLE devices
>
> Step 2:
>
> 4: close BLE scanner app
> 5: open BLE scanner app
> 6: app cannot find any BLE device
>
>
> - Szymon has suggested it is related to duplicate filtering and may be
> handled at the driver or chipset firmware level.
>
> - I found this post which might provide some useful background info.
>
> http://stackoverflow.com/questions/19502853/android-4-3-ble-filtering-behaviour-of-startlescan
>
> - My question is can I do anything at the driver/kernel/bluez level so
> that BLE devices always show up?
so we are always using the duplicate filtering of the controller. Not using it will cause an overflow of advertising reports in a busy environment.
The difference between certain manufactures is that some filter strictly only on address, other filter on address + RSSI. Meaning that if the RSSI changes you get another event. What I know is that Broadcom is in the first camp and CSR/TI are in the second camp.
This means that if you care about devices found on a constant basis and depend on the RSSI changing, you need to stop and restart the LE scan for at least Broadcom based controllers. I have no idea in what camp the Realtek one falls since I yet have to get one of these.
On an independent thread we are talking about adding a quirk to our internal discovery handling to automatically restart scan for the controllers that do the strict filtering based on address only.
Regards
Marcel