esp-idf: ESP peripheral + iOS 13.4: ignored BLE attribute read by type (IDFGH-2843)

Environment

• Development Kit: none (custom HW)
• Module or chip used: ESP32-WROOM-32
• IDF version (run git describe --tags to find it): v4.1-dev-369-g4dac7c7df
• Build System: CMake
• Compiler version (run xtensa-esp32-elf-gcc --version to find it): gcc8_2_0-esp-2019r1-linux-amd64
• Operating System: Linux
• Using an IDE?: No
• Power Supply: external 3.3V

Problem Description

We have our ESP configured as a GATT server, and have Android and iOS apps that connect to it. However, we have just begun having a problem with iPhones running iOS 13.4, and only those iPhones which also support Bluetooth 5.

It looks like a failure of the BLE stack to process a GATT Read By Type request for the device model string in the device information service shortly after discovery. 30 seconds later, the iOS device disconnects because it never receives a response.

In the ESP debug (BLE GATT and L2CAP debug is turned on), I can see that it receives a message:

D (219742) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

But there’s nothing else until the disconnect message 30s later, whereas there’s lots of L2CAP debug for all other messages. It’s as if the stack is just ignoring it.

I’ve attached a WireShark log, and the ESP debug log follows.

E (200913) Heap: 83000
E (200913) HeapMin: 78000
E (210913) Heap: 82992
E (210913) HeapMin: 78000
D (215435) BT_L2CAP: l2c_ble_link_adjust_allocation  num_hipri: 0  num_lowpri: 1  low_quota: 10  round_robin_quota: 0  qq: 10
D (215435) BT_L2CAP: l2c_ble_link_adjust_allocation LCB 0   Priority: 0  XmitQuota: 10
D (215436) BT_L2CAP:         SentNotAcked: 0  RRUnacked: 0
D (215437) BT_L2CAP: l2cu_allocate_ccb: cid 0x0000
D (215438) BT_L2CAP: l2c_link_adjust_chnl_allocation
D (215438) BT_L2CAP: CID:0x0043 FCR Mode:0 Priority:2 TxDataRate:1 RxDataRate:1 Quota:200
D (215572) BT_L2CAP: l2cu_process_fixed_chnl_resp
D (215572) BT_GATT: GATT   ATT protocol channel with BDA: 52c52dd739e1 is connected
D (215572) BT_GATT: gatt_is_bda_in_the_srv_chg_clt_list :52-c5-2d-d7-39-e1
D (215573) BT_GATT: gatt_set_ch_state: old=0 new=4
D (215573) BT_GATT: gatt_connect_cback: from 52c52dd739e1 connected:1 conn_id=1 reason = 0x0000
D (215575) BT_GATT: gatt_get_ch_state: ch_state=4
I (215575) BT_GATT: GATT_GetConnIdIfConnected status=1

D (215578) BT_GATT: gatt_num_apps_hold_link   num=0
I (215578) BT_L2CAP: L2CA_SetDesireRole() new:x1, disallow_switch:0
I (215580) Esp Ble Server: gatt server event: ESP_GATTS_CONNECT_EVT on interface: 4
I (215581) Esp Ble Server: phone connected!
I (215581) Esp Ble Server: Restart advertising due to connect.
I (215582) Esp Ble Client: gatt server event: ESP_GATTC_CONNECT_EVT on interface: 3
E (215583) Esp Ble Client: Connection to E1:39:D7:2D:C5:52 was started when connection to 00:00:00:00:00:00 was already in progress.
I (215583) GOT ACK!:
D (215585) BT_L2CAP: l2c_link_check_send_pkts
D (215585) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215586) BT_L2CAP: l2c_link_send_to_lower
D (215587) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
I (215590) SEND ACK!:
I (215591) Ble Driver: GAP event: ESP_GAP_BLE_ADV_START_COMPLETE_EVT
I (215591) Ble Driver: Advertising Succeeded!
D (215631) BT_L2CAP: l2c_link_check_send_pkts
D (215631) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215631) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (215632) BT_L2CAP: l2cble_process_data_length_change_event TX data len = 251
D (215662) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (215662) BT_GATT: gatt_get_ch_state: ch_state=4
I (215662) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (215663) BT_L2CAP: l2c_link_check_send_pkts
D (215663) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215665) BT_L2CAP: l2c_link_send_to_lower
D (215665) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (215665) BT_GATT: gatt_request_cback
D (215666) BT_GATT: Get MTU exchange new mtu size: 247
I (215667) BT_GATT: GATT_GetConnectionInfor conn_id=4
D (215670) BT_L2CAP: L2CAP - rcv_cid CID: 0x0005

I (215672) Esp Ble Server: gatt server event: ESP_GATTS_MTU_EVT on interface: 4
I (215673) Esp Ble Server: ESP_GATTS_MTU_EVT, MTU 247, conn_id: 0
I (215673) Ble Driver: GAP event: ESP_GAP_BLE_UPDATE_CONN_PARAMS_EVT
E (215676) Ble Driver: update connection params for E1:39:D7:2D:C5:52: status = 15, min_int = 32, max_int = 32,conn_int = 24,latency = 0, timeout = 72
D (215721) BT_L2CAP: l2c_link_check_send_pkts
D (215721) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215721) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (215722) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (215723) BT_GATT: gatt_get_ch_state: ch_state=4
I (215723) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (215724) BT_L2CAP: l2c_link_check_send_pkts
D (215725) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215727) BT_L2CAP: l2c_link_send_to_lower
D (215728) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (215841) BT_L2CAP: l2c_link_check_send_pkts
D (215841) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215841) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (215842) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (215842) BT_GATT: gatt_get_ch_state: ch_state=4
I (215843) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (215844) BT_L2CAP: l2c_link_check_send_pkts
D (215845) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215845) BT_L2CAP: l2c_link_send_to_lower
D (215847) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (215931) BT_L2CAP: l2c_link_check_send_pkts
D (215931) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215931) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (215932) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (215933) BT_GATT: gatt_get_ch_state: ch_state=4
D (215933) BT_GATT: Use 0xFFFF for the last primary attribute
I (215934) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (215935) BT_L2CAP: l2c_link_check_send_pkts
D (215936) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215936) BT_L2CAP: l2c_link_send_to_lower
D (215937) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (215991) BT_L2CAP: l2c_link_check_send_pkts
D (215991) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215991) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (215992) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (215993) BT_GATT: gatt_get_ch_state: ch_state=4
D (215993) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (215994) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (215995) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (215996) BT_L2CAP: l2c_link_check_send_pkts
D (215997) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (215997) BT_L2CAP: l2c_link_send_to_lower
D (215998) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216051) BT_L2CAP: l2c_link_check_send_pkts
D (216051) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216051) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216052) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216053) BT_GATT: gatt_get_ch_state: ch_state=4
D (216053) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

I (216054) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216055) BT_L2CAP: l2c_link_check_send_pkts
D (216056) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216058) BT_L2CAP: l2c_link_send_to_lower
D (216058) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216111) BT_L2CAP: l2c_link_check_send_pkts
D (216111) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216111) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216112) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216113) BT_GATT: gatt_get_ch_state: ch_state=4
I (216114) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216114) BT_L2CAP: l2c_link_check_send_pkts
D (216115) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216116) BT_L2CAP: l2c_link_send_to_lower
D (216117) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216171) BT_L2CAP: l2c_link_check_send_pkts
D (216171) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216172) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216172) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216173) BT_GATT: gatt_get_ch_state: ch_state=4
I (216174) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216175) BT_L2CAP: l2c_link_check_send_pkts
D (216175) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216176) BT_L2CAP: l2c_link_send_to_lower
D (216177) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216231) BT_L2CAP: l2c_link_check_send_pkts
D (216231) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216231) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216232) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216233) BT_GATT: gatt_get_ch_state: ch_state=4
D (216233) BT_GATT: gatts_write_attr_perm_check op_code=0x12 handle=0x0004 offset=0 len=2 sec_flag=0x0 key_size=0
D (216234) BT_GATT: gatts_write_attr_perm_check p_attr->permission =0x0011 min_key_size==0x0000
D (216236) BT_GATT: gatt_request_cback
D (216236) BT_GATT: GATTS_SetAttributeValue: attr_handle: 4  length: 2

I (216237) BT_GATT: GATTS_SendRsp: conn_id: 1  trans_id: 1  Status: 0x0000

D (216238) BT_GATT: gatt_sr_process_app_rsp gatt_if=1

I (216239) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216239) BT_L2CAP: l2c_link_check_send_pkts
D (216240) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216241) BT_L2CAP: l2c_link_send_to_lower
D (216242) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216242) BT_GATT: gatt_dequeue_sr_cmd
D (216243) BT_GATT: gatt_sr_process_app_rsp ret_code=0

D (216351) BT_L2CAP: l2c_link_check_send_pkts
D (216351) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216351) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216352) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216353) BT_GATT: gatt_get_ch_state: ch_state=4
D (216353) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (216354) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216357) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216358) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216359) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (216360) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216361) BT_L2CAP: l2c_link_check_send_pkts
D (216361) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216362) BT_L2CAP: l2c_link_send_to_lower
D (216363) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216411) BT_L2CAP: l2c_link_check_send_pkts
D (216411) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216411) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216412) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216413) BT_GATT: gatt_get_ch_state: ch_state=4
D (216413) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (216414) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216415) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (216416) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216417) BT_L2CAP: l2c_link_check_send_pkts
D (216418) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216419) BT_L2CAP: l2c_link_send_to_lower
D (216419) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216471) BT_L2CAP: l2c_link_check_send_pkts
D (216471) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216471) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216472) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216472) BT_GATT: gatt_get_ch_state: ch_state=4
D (216473) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (216474) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216475) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216476) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216477) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

D (216478) BT_GATT: read_attr_value uuid=0x2803 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (216479) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216480) BT_L2CAP: l2c_link_check_send_pkts
D (216481) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216482) BT_L2CAP: l2c_link_send_to_lower
D (216482) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216531) BT_L2CAP: l2c_link_check_send_pkts
D (216531) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216531) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216532) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216533) BT_GATT: gatt_get_ch_state: ch_state=4
D (216533) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

I (216534) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216535) BT_L2CAP: l2c_link_check_send_pkts
D (216536) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216536) BT_L2CAP: l2c_link_send_to_lower
D (216537) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216591) BT_L2CAP: l2c_link_check_send_pkts
D (216591) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216591) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216592) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216593) BT_GATT: gatt_get_ch_state: ch_state=4
I (216593) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216594) BT_L2CAP: l2c_link_check_send_pkts
D (216595) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216596) BT_L2CAP: l2c_link_send_to_lower
D (216597) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216651) BT_L2CAP: l2c_link_check_send_pkts
D (216651) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216651) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216652) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216653) BT_GATT: gatt_get_ch_state: ch_state=4
I (216653) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216654) BT_L2CAP: l2c_link_check_send_pkts
D (216655) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216656) BT_L2CAP: l2c_link_send_to_lower
D (216656) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216711) BT_L2CAP: l2c_link_check_send_pkts
D (216711) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216711) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (216712) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (216712) BT_GATT: gatt_get_ch_state: ch_state=4
I (216713) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (216714) BT_L2CAP: l2c_link_check_send_pkts
D (216715) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216716) BT_L2CAP: l2c_link_send_to_lower
D (216716) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (216800) BT_L2CAP: l2c_link_check_send_pkts
D (216800) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (216801) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (218691) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (218691) BT_GATT: gatt_get_ch_state: ch_state=4
D (218691) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (218691) BT_GATT: read_attr_value uuid=0x2a00 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (218693) BT_GATT: GATTS_SendRsp: conn_id: 2  trans_id: 2  Status: 0x0000

D (218693) BT_GATT: gatt_sr_process_app_rsp gatt_if=2

I (218694) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (218695) BT_L2CAP: l2c_link_check_send_pkts
D (218696) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (218697) BT_L2CAP: l2c_link_send_to_lower
D (218697) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
D (218698) BT_GATT: gatt_dequeue_sr_cmd
D (218698) BT_GATT: gatt_sr_process_app_rsp ret_code=0

D (218750) BT_L2CAP: l2c_link_check_send_pkts
D (218751) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (218751) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (219681) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (219681) BT_GATT: gatt_get_ch_state: ch_state=4
D (219681) BT_GATT: gatts_process_read_by_type_req, op_code =8, len = 0

D (219682) BT_GATT: read_attr_value uuid=0x2a29 perm=0x1 sec_flag=0x0 offset=0 read_long=0

I (219683) BT_GATT: GATT_GetConnectionInfor conn_id=4
I (219685) BT_L2CAP: L2CA_SendFixedChnlData()  CID: 0x0004  BDA: 52c52dd739e1
D (219685) BT_L2CAP: l2c_link_check_send_pkts
D (219685) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (219686) BT_L2CAP: l2c_link_send_to_lower
D (219687) BT_L2CAP: TotalWin=9,Hndl=0x0,Quota=10,Unack=1,RRQuota=0,RRUnack=0
I (219688) Esp Ble Server: gatt server event: ESP_GATTS_READ_EVT on interface: 4
I (219689) Esp Ble Server: read event: conn_id 0, handle 58 [2A29], is_long 0, need_rsp 0, offset 0, trans_id 3
D (219741) BT_L2CAP: l2c_link_check_send_pkts
D (219741) BT_L2CAP: partial_segment_being_sent=0,link_state=4,power_mode=0
D (219741) BT_L2CAP: TotalWin=10,LinkUnack(0x0)=0,RRCheck=0,RRUnack=0

D (219742) BT_L2CAP: L2CAP - rcv_cid CID: 0x0004

D (219742) BT_GATT: gatt_get_ch_state: ch_state=4
E (220913) Heap: 81292
E (220913) HeapMin: 78000
V (225622) esp_adapter: thread sem get: sem=0x3ffe8098
D (227672) event: running post WIFI_EVENT:1 with handler 0x400e2ac4 on loop 0x3ffcbb24
E (227672) ESP Wifi: Event received: WIFI_EVENT_SCAN_DONE
V (227724) esp_adapter: thread sem get: sem=0x3ffe8098
E (230913) Heap: 80812
E (230913) HeapMin: 78000
E (240913) Heap: 81444
E (240913) HeapMin: 78000
D (249710) BT_L2CAP: l2cu_release_ccb: cid 0x0004  in_use: 1
D (249710) BT_GATT: GATT   ATT protocol channel with BDA: 52c52dd739e1 is disconnected
D (249711) BT_GATT: gatt_is_bda_in_the_srv_chg_clt_list :52-c5-2d-d7-39-e1
D (249712) BT_GATT: gatt_cleanup_upon_disc
D (249712) BT_GATT: found p_tcb
D (249713) BT_GATT: gatt_set_ch_state: old=4 new=0
D (249713) BT_GATT: gatt_free_pending_ind
D (249714) BT_GATT: gatt_free_pending_enc_queue
D (249714) BT_GATT: gatt_free_pending_prepare_write_queue
D (249715) BT_GATT: found p_reg tcb_idx=0 gatt_if=1  conn_id=0x1
D (249716) BT_GATT: gatt_connect_cback: from 52c52dd739e1 connected:0 conn_id=1 reason = 0x0013
D (249717) BT_GATT: gatt_get_ch_state: ch_state=0
I (249717) BT_GATT: GATT_GetConnIdIfConnected status=0

D (249718) BT_GATT: found p_reg tcb_idx=0 gatt_if=2  conn_id=0x2
D (249719) BT_GATT: found p_reg tcb_idx=0 gatt_if=3  conn_id=0x3
W (249720) BT_APPL: bta_gattc_conn_cback() - cif=3 connected=0 conn_id=3 reason=0x0013
D (249721) BT_GATT: found p_reg tcb_idx=0 gatt_if=4  conn_id=0x4
D (249722) BT_GATT: gatt_delete_dev_from_srv_chg_clt_list
D (249722) BT_GATT: gatt_is_bda_in_the_srv_chg_clt_list :52-c5-2d-d7-39-e1
D (249723) BT_GATT: ATT disconnected
I (249724) BT_L2CAP: L2CA_SetDesireRole() new:x1, disallow_switch:0
I (249725) Esp Ble Server: gatt server event: ESP_GATTS_DISCONNECT_EVT on interface: 4
I (249725) Esp Ble Server: phone disconnect!
I (249726) Esp Ble Server: Restart advertising due to disconnect.
I (249727) Esp Ble Client: gatt server event: ESP_GATTC_DISCONNECT_EVT on interface: 3
I (249728) Esp Ble Client: connection failed for unknown device
I (249728) GOT ACK!:
I (249729) Esp Ble Client: 52 c5 2d d7 39 e1
I (249730) Esp Ble Client: Restart scanning due to disconnect
I (249736) Ble Driver: GAP event: ESP_GAP_BLE_ADV_START_COMPLETE_EVT
I (249736) Ble Driver: Advertising Succeeded!
E (250913) Heap: 82952
E (250913) HeapMin: 78000
I (252590) SEND ACK!:
V (257724) esp_adapter: thread sem get: sem=0x3ffe8098
D (259774) event: running post WIFI_EVENT:1 with handler 0x400e2ac4 on loop 0x3ffcbb24
E (259774) ESP Wifi: Event received: WIFI_EVENT_SCAN_DONE
V (259827) esp_adapter: thread sem get: sem=0x3ffe8098
I (259990) SEND ACK!:
E (260913) Heap: 83484
E (260913) HeapMin: 78000

iOS_ConnFail_BLE5.pcapng.log