android4.3上的蓝牙4.0

前几天客户寄了个睡眠监测器，说是蓝牙4.0的设备。
这个设备在IMX6Q平台android4.3系统上有时可以搜索到有时又搜索不到，
其他的蓝牙4.0设备都可以搜索到。
搜索不到时的logcat打印信息如下：
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
E/BTLD ( 3157): ######################################################################
E/BTLD ( 3157): #
E/BTLD ( 3157): # WARNING : BTU HCI(id=0) command timeout. opcode=0x2008
E/BTLD ( 3157): #
E/BTLD ( 3157): ######################################################################
W/bt-hci ( 3157): HCI Cmd timeout counter 1
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x02)
I/bt-hci ( 3157): btu_ble_process_adv_pkt
D/BluetoothEventManager( 3073): DeviceFoundHandler created new CachedBluetoothDevice: 68:3E:34:93:99:6A
D/dalvikvm( 3073): GC_CONCURRENT freed 329K, 10% free 3670K/4052K, paused 2ms+4ms, total 22ms
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x01)
W/bt-btif ( 3157): info:x0
D/ ( 3157): remote version info [ec:11:27:6f:8b:aa]: 0, 0, 0
D/btif_config_util( 3157): btif_config_save_file(L153): in file name:/data/misc/bluedroid/bt_config.new
E/BluetoothRemoteDevices( 3157): aclStateChangeCallback: Device is NULL
I/bt-hci ( 3157): BLE HCI(id=62) event = 0x04)
E/bt-btm ( 3157): btm_sec_disconnected - Clearing Pending flag
E/BluetoothRemoteDevices( 3157): aclStateChangeCallback: Device is NULL
I/AudioService( 2865): AudioFocus abandonAudioFocus() from android.media.AudioManager@419abb90com.android.music.MediaPlaybackService$3@419aaab0
I/ActivityManager( 2865): Start proc com.android.musicfx for broadcast com.android.musicfx/.ControlPanelReceiver: pid=3437 uid=10027 gids={50027, 3003, 3002, 1028}
V/MusicFXControlPanelReceiver( 3437): onReceive
V/MusicFXControlPanelReceiver( 3437): Action: android.media.action.CLOSE_AUDIO_EFFECT_CONTROL_SESSION
V/MusicFXControlPanelReceiver( 3437): Package name: com.android.music
V/MusicFXControlPanelReceiver( 3437): Audio session: 7
V/MusicFXControlPanelEffect( 3437): closeSession(android.app.ReceiverRestrictedContext@419a8c70, com.android.music, 7)

搜索到的时候不会打印 " Device is NULL" ，但是这个设备在android6.0的平板电脑上却可以稳定搜索到。
各位大神这个究竟是什么问题，是应用层还是驱动层出了问题呢。
跪求这个设备能在android4.3上稳定搜索到的解决方法，小弟感激不尽。

先换一些环境测试下，单个样品这个不好说。