1）關閉/打開手機端藍牙， 之前連接的設備（包括headset&HID etc）可以自動重連。
問題，不重連。
原因：
--關閉藍牙時候手機端資源清理不乾淨，還有鏈路保持連接
--headset發起自動重連，但是被手機拒絕， fix 方法：手機在藍牙起來之後，嘗試連接之前連接的設備。
IO Capability Request Reply (0x01|0x002b) ncmd 1
status 0x00 bdaddr 00:0D:FD:71:53:02
2010-10-07 17:47:12.782403 > HCI Event: Simple Pairing Complete (0x36) plen 7
status 0x05 bdaddr 00:0D:FD:71:53:02
Error: Authentication Failure
2010-10-07 17:47:12.782434 > HCI Event: Auth Complete (0x06) plen 3
status 0x05 handle 12
Error: Authentication Failure
2010-10-07 17:47:12.782438 > HCI Event: Disconn Complete (0x05) plen 4
status 0x00 handle 12 reason 0x08
Reason: Connection Timeout
其他原因，待補充
2）2個基於L2CAP的profile同時使用，可能會有延遲。
比如在A2DP聽音樂時候，敲擊HID鍵盤，或者傳送大文件，都可能使音樂卡，一般是跟藍牙帶寬有關係，需要bluetooth firmware更新
3）某些藍牙耳機在聽歌時候，來了電話，這時候藍牙斷開。
原因：
看不到LMP_detach 或者L2CAP disconnect ，而是libaudio.so的crash，導致bluetoothd crash，連接斷開。
發現是因爲這些耳機本身的bug，the timing of switching between SCO and A2DP; slowing that process tends to reduce the rate of occurrence.
SCO和A2DP切換慢些，可以避免這些問題發生。
4）out of range, and reconnection issue.
out of range時候，手機收到
> HCI Event: Disconn Complete (0x05) plen 4
status 0x00 handle 12 reason 0x08
Reason: Connection Timeout
2011-02-05 15:36:55.456681 < HCI Command: Delete Stored Link Key (0x03|0x0012) p
len 7
bdaddr 00:1F:20:01:C9:B8 all 0
2011-02-05 15:36:55.465888 > HCI Event: Command Complete (0x0e) plen 6
Delete Stored Link Key (0x03|0x0012) ncmd 1
status 0x00 deleted 0
2011-02-05 15:37:00.665401 > HCI Event: Connect Request (0x04) plen 10
bdaddr 00:1F:20:01:C9:B8 class 0x002580 type ACL
2011-02-05 15:37:00.665547 < HCI Command: Accept Connection Request (0x01|0x0009
) plen 7
bdaddr 00:1F:20:01:C9:B8 role 0x00
Role: Master
2011-02-05 15:37:00.675457 > HCI Event: Command Status (0x0f) plen 4
Accept Connection Request (0x01|0x0009) status 0x00 ncmd 1
2011-02-05 15:37:00.835340 > HCI Event: Role Change (0x12) plen 8
status 0x00 bdaddr 00:1F:20:01:C9:B8 role 0x00
Role: Master
2011-02-05 15:37:00.985466 > HCI Event: Connect Complete (0x03) plen 11
status 0x00 handle 11 bdaddr 00:1F:20:01:C9:B8 type ACL encrypt 0x00
2011-02-05 15:37:00.985564 < HCI Command: Read Remote Supported Features (0x01|0
x001b) plen 2
handle 11
2011-02-05 15:37:00.999921 > HCI Event: Command Status (0x0f) plen 4
Read Remote Supported Features (0x01|0x001b) status 0x00 ncmd 1
2011-02-05 15:37:00.999931 > HCI Event: Read Remote Supported Features (0x0b) pl
en 11
status 0x00 handle 11
Features: 0xbc 0x02 0x04 0x38 0x08 0x00 0x00 0x00
2011-02-05 15:37:01.015228 > ACL data: handle 11 flags 0x02 dlen 12
L2CAP(s): Connect req: psm 17 scid 0x0057
2011-02-05 15:37:01.015292 < ACL data: handle 11 flags 0x00 dlen 16
0000: 0c 00 01 00 03 1e 08 00 40 00 57 00 01 00 00 00 [email protected].....
2011-02-05 15:37:01.015356 < ACL data: handle 11 flags 0x00 dlen 10
0000: 06 00 01 00 0a 01 02 00 02 00 ..........
2011-02-05 15:37:01.025413 > HCI Event: Number of Completed Packets (0x13) plen
5
handle 11 packets 2
2011-02-05 15:37:01.039257 < HCI Command: Remote Name Request (0x01|0x0019) plen
10
bdaddr 00:1F:20:01:C9:B8 mode 2 clkoffset 0x0000
2011-02-05 15:37:01.045429 > HCI Event: Command Status (0x0f) plen 4
Remote Name Request (0x01|0x0019) status 0x00 ncmd 1
2011-02-05 15:37:01.045436 > ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Info rsp: type 2 result 0
Extended feature mask 0x0004
Bi-directional QoS
2011-02-05 15:37:01.045752 < ACL data: handle 11 flags 0x00 dlen 16
0000: 0c 00 01 00 03 1e 08 00 40 00 57 00 00 00 00 00 [email protected].....
2011-02-05 15:37:01.095183 > ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 4
MTU 185
2011-02-05 15:37:01.095233 < ACL data: handle 11 flags 0x00 dlen 18
0000: 0e 00 01 00 05 1f 0a 00 57 00 00 00 00 00 01 02 ........W.......
0010: b9 00 ?
2011-02-05 15:37:01.095286 < ACL data: handle 11 flags 0x00 dlen 12
0000: 08 00 01 00 04 02 04 00 57 00 00 00 ........W...
2011-02-05 15:37:01.105263 > HCI Event: Number of Completed Packets (0x13) plen
5
handle 11 packets 2
2011-02-05 15:37:01.105271 > HCI Event: Remote Name Req Complete (0x07) plen 255
status 0x00 bdaddr 00:1F:20:01:C9:B8 name 'Bluetooth Laser Travel Mouse'
2011-02-05 15:37:01.135268 > ACL data: handle 11 flags 0x02 dlen 18
L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 4
MTU 185
2011-02-05 15:37:01.135280 > ACL data: handle 11 flags 0x02 dlen 12
L2CAP(s): Connect req: psm 19 scid 0x0058
2011-02-05 15:37:01.135357 < ACL data: handle 11 flags 0x00 dlen 16
0000: 0c 00 01 00 03 20 08 00 41 00 58 00 01 00 02 00 ..... ..A.X.....
2011-02-05 15:37:01.136721 < ACL data: handle 11 flags 0x00 dlen 12
0000: 08 00 01 00 06 03 04 00 57 00 40 00 ........W.@.
2011-02-05 15:37:01.145269 > HCI Event: Number of Completed Packets (0x13) plen
5
handle 11 packets 2
2011-02-05 15:37:01.146256 < ACL data: handle 11 flags 0x00 dlen 16
0000: 0c 00 01 00 03 20 08 00 41 00 58 00 03 00 00 00 ..... ..A.X.....
2011-02-05 15:37:01.155415 > ACL data: handle 11 flags 0x02 dlen 12
L2CAP(s): Disconn rsp: dcid 0x0057 scid 0x0040
2011-02-05 15:37:01.155426 > HCI Event: Number of Completed Packets (0x13) plen
5
handle 11 packets 2
2011-02-05 15:37:08.446384 < HCI Command: Authentication Requested (0x01|0x0011)
plen 2
handle 11
2011-02-05 15:37:08.459101 > HCI Event: Command Status (0x0f) plen 4
Authentication Requested (0x01|0x0011) status 0x00 ncmd 1
2011-02-05 15:37:08.459117 > HCI Event: Link Key Request (0x17) plen 6
bdaddr 00:1F:20:01:C9:B8
2011-02-05 15:37:08.465568 < HCI Command: Link Key Request Negative Reply (0x01|
0x000c) plen 6
bdaddr 00:1F:20:01:C9:B8
2011-02-05 15:37:08.475370 > HCI Event: Command Complete (0x0e) plen 10
Link Key Request Negative Reply (0x01|0x000c) ncmd 1
status 0x00 bdaddr 00:1F:20:01:C9:B8
2011-02-05 15:37:08.475382 > HCI Event: PIN Code Request (0x16) plen 6
bdaddr 00:1F:20:01:C9:B8
2011-02-05 15:37:13.785296 > HCI Event: Auth Complete (0x06) plen 3
status 0x16 handle 11
Error: Connection Terminated by Local Host
2011-02-05 15:37:13.785316 > HCI Event: Disconn Complete (0x05) plen 4
status 0x00 handle 11 reason 0x16
Reason: Connection Terminated by Local Host
本質上還是有些資源沒有釋放。。。。