Hi,
There seems to be an issue somewhere between the hci_usb sample, zephyr, and bluez on linux. It's really easy to recreate the issue for me:
- Flash an nrf52840 dongle with the
hci_usbsample - flash any nordic board with a ble sample like I have peripheral hr
- connect dongle to linux host, using
bluetoothctlscan and connect to the nordic board - Using btmon to log the initial connection, when there is NO cache (the linux host has NEVER connected to this board before), I can see it gets to the MTU negotiation and then times out, and disconnects
On second attempt the connection always succeeds, and then further connection attemps always do succeed, but if I delete the bluetooth cache from /var/lib/bluetooth/ and reconnect, the same issue occurs on the first connection attempt. I'm not sure where exactly the issue lays but with those exact steps I'm able to recreate it constantly. Here is the btmon log when I connect to the device:
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6 #174 [hci0] 13.870590
Address: E2:25:60:FB:F0:A7 (Static)
> HCI Event: Command Complete (0x0e) plen 4 #175 [hci0] 13.877470
LE Set Random Address (0x08|0x0005) ncmd 1
Status: Success (0x00)
< HCI Command: LE Add Device To Accept List (0x08|0x0011) plen 7 #176 [hci0] 13.878615
Address type: Random (0x01)
Address: E4:05:AA:E4:7B:4E (Static)
> HCI Event: Command Complete (0x0e) plen 4 #177 [hci0] 13.880710
LE Add Device To Accept List (0x08|0x0011) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #178 [hci0] 13.881419
Type: Passive (0x00)
Interval: 60.000 msec (0x0060)
Window: 60.000 msec (0x0060)
Own address type: Random (0x01)
Filter policy: Ignore not in accept list (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #179 [hci0] 13.883711
LE Set Scan Parameters (0x08|0x000b) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #180 [hci0] 13.883755
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #181 [hci0] 13.885864
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 23 #182 [hci0] 13.945714
LE Advertising Report (0x02)
Num reports: 1
Event type: Connectable undirected - ADV_IND (0x00)
Address type: Random (0x01)
Address: E4:05:AA:E4:7B:4E (Static)
Data length: 11
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
16-bit Service UUIDs (complete): 3 entries
Heart Rate (0x180d)
Battery Service (0x180f)
Device Information (0x180a)
RSSI: -51 dBm (0xcd)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #183 [hci0] 13.945976
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 #184 [hci0] 13.948713
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25 #185 [hci0] 13.948957
Scan interval: 60.000 msec (0x0060)
Scan window: 60.000 msec (0x0060)
Filter policy: Accept list is not used (0x00)
Peer address type: Random (0x01)
Peer address: E4:05:AA:E4:7B:4E (Static)
Own address type: Random (0x01)
Min connection interval: 30.00 msec (0x0018)
Max connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Min connection length: 0.000 msec (0x0000)
Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4 #186 [hci0] 13.952002
LE Create Connection (0x08|0x000d) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 31 #187 [hci0] 14.062627
LE Enhanced Connection Complete (0x0a)
Status: Success (0x00)
Handle: 0
Role: Central (0x00)
Peer address type: Random (0x01)
Peer address: E4:05:AA:E4:7B:4E (Static)
Local resolvable private address: 00:00:00:00:00:00 (Non-Resolvable)
Peer resolvable private address: 00:00:00:00:00:00 (Non-Resolvable)
Connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Central clock accuracy: 0x00
@ MGMT Event: Device Connected (0x000b) plen 24 {0x0001} [hci0] 14.062729
LE Address: E4:05:AA:E4:7B:4E (Static)
Flags: 0x00000008
Connection Locally Initiated
Data length: 11
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
16-bit Service UUIDs (complete): 3 entries
Heart Rate (0x180d)
Battery Service (0x180f)
Device Information (0x180a)
> HCI Event: LE Meta Event (0x3e) plen 4 #188 [hci0] 14.064959
LE Channel Selection Algorithm (0x14)
Handle: 0
Algorithm: #2 (0x01)
< HCI Command: LE Read Remote Used Features (0x08|0x0016) plen 2 #189 [hci0] 14.081529
Handle: 0
> HCI Event: Command Status (0x0f) plen 4 #190 [hci0] 14.085101
LE Read Remote Used Features (0x08|0x0016) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 11 #191 [hci0] 14.280425
LE Data Length Change (0x07)
Handle: 0
Max TX octets: 27
Max TX time: 2120
Max RX octets: 27
Max RX time: 2120
> HCI Event: LE Meta Event (0x3e) plen 12 #192 [hci0] 14.334617
LE Read Remote Used Features (0x04)
Status: Success (0x00)
Handle: 0
Features: 0x2d 0x41 0x00 0x00 0x00 0x00 0x00 0x00
LE Encryption
Extended Reject Indication
Peripheral-initiated Features Exchange
LE Data Packet Length Extension
LE 2M PHY
Channel Selection Algorithm #2
= bluetoothd: src/device.c:load_gatt_db() No cache for E4:05:AA:E4:7B:4E 14.336637
< ACL Data TX: Handle 0 flags 0x00 dlen 7 #193 [hci0] 14.337850
ATT: Exchange MTU Request (0x02) len 2
Client RX MTU: 517
> HCI Event: Number of Completed Packets (0x13) plen 5 #194 [hci0] 14.388916
Num handles: 1
Handle: 0
Count: 1
