Re: [Zephyr-devel] Zephyr IPSP sample crashes and ble controller crashes (IPv6 over BLE)

Luiz Augusto von Dentz

Hi Priyanka,

Current IPSP configuration only works with Linux kernel version 4.12
or later, zephyr 1.9 used to have the infamous ZEP1656 config option
set which has been removed in 1.10.

On Tue, Dec 12, 2017 at 1:55 PM, Priyanka Rawat <> wrote:
Hi Luiz

The HCI firmware hci_blackbox is from KW41Z SDK2.2.

BLE controller remains connected and bt0 does not go down if most of the
debug logs are disabled in prj.conf

As with debug logs enabled, it prints error

[bt] [ERR] read_payload: Not enough space in buffer

With my test set up k64f (zephyr IPSP)+ kw41z (ble controller), host flow
control is not enabled.

[bt] [WRN] set_flow_control: Controller to host flow control not supported

I wonder if we can enable UART flow control on frdm_k64f for HCI transport
with frdm_kw41z?

[Kw41z (ble controller)+ k64f (zephyr IPSP)] <---------->[Kw41z (ble
controller)+Linux host]

In addition, with recent zephyr master, I have another issue, while testing
with sample IPSP, ping fails.

Please note I did not have this issue with zephyr-1.9.1. With same
configurations, ping worked fine with zephyr-1.9.1

Issue with IPSP sample (recent master branch) :

BLE address is assigned to k64f board. bluetoothctl utility and its scan
discover IPSP node.
BLE connection is up, interface bt0 is up.
On zephyr side, iface shows interface bluetooth.

Ping to k64f board fails. Ping from Zephyr side to Linux host fails.

Wireshark capture shows Multicast Listener Report Message V2,

Neighbor Solicitation for 2001:db8::2



[bt] [WRN] set_flow_control: Controller to host flow control not supported
[bt] [WRN] hci_vs_init: Vendor HCI extensions not available
[bt] [INF] show_dev_info: Identity: 00:04:9f:00:00:15 (public)
[bt] [INF] show_dev_info: HCI: version 4.2 (0x08) revision 0x000b,
manufacturer 0x0025
[bt] [INF] show_dev_info: LMP: version 4.2 (0x08) subver 0x0121
[bt] [DBG] bt_l2cap_le_fixed_chan_register: (0x20001998) CID 0x0004
[bt] [DBG] bt_l2cap_le_fixed_chan_register: (0x20001998) CID 0x0006
[bt] [DBG] bt_smp_init: (0x20001998) LE SC enabled
[bt] [DBG] bt_l2cap_le_fixed_chan_register: (0x20001998) CID 0x0005
[bt] [DBG] bt_smp_pkey_ready: (0x200003b4)
[ipsp] [INF] init_app: Run IPSP sample

[ipsp] [ERR] get_context: Cannot bind IPv6 mcast (-2)
[ipsp] [ERR] listen: Cannot get network contexts

[bt] [DBG] bt_keys_find_irk: (0x200003b4) 00:60:37:00:00:16 (public)
[bt] [DBG] bt_l2cap_chan_add: (0x200003b4) conn 0x200008d4 chan 0x20000a28
[bt] [DBG] bt_smp_accept: (0x200003b4) conn 0x200008d4 handle 32

net> ping 2001:db8::2
Sent a ping to 2001:db8::2
[bt] [DBG] bt_l2cap_chan_send: (0x20001210) chan 0x20009bcc buf 0x20006e48
len 57
[bt] [DBG] l2cap_chan_create_seg: (0x20001210) ch 0x20009bcc seg 0x20006c8c
len 59
[bt] [DBG] l2cap_chan_le_send: (0x20001210) ch 0x20009bcc cid 0x0040 len 59
credits 4
[bt] [DBG] bt_l2cap_send_cb: (0x20001210) conn 0x200008d4 cid 64 len 59
[bt] [DBG] l2cap_chan_le_send_sdu: (0x20001210) ch 0x20009bcc cid 0x0040
sent 57 total_len 57
Ping timeout
net> iface

Interface 0x2000a020 (Bluetooth)
Link addr : 00:04:9F:00:00:15
MTU : 1280
IPv6 unicast addresses (max 3):
2001:db8::1 manual preferred infinite
fe80::4:9fff:fe00:15 autoconf preferred infinite
IPv6 multicast addresses (max 2):
IPv6 prefixes (max 2):
IPv6 hop limit : 64
IPv6 base reachable time : 30000
IPv6 reachable time : 17260
IPv6 retransmit timer : 0


From: Luiz Augusto von Dentz <>
Sent: Tuesday, December 5, 2017 6:23 PM
To: Priyanka Rawat
Subject: Re: [Zephyr-devel] Zephyr IPSP sample crashes and ble controller
crashes (IPv6 over BLE)

Hi Priyanka,

On Tue, Dec 5, 2017 at 5:30 PM, Priyanka Rawat <>

My test set up for IPv6 over BLE is following :

At one end : Two boards frdm-kw41z and frdm-k64f are stacked together.
kw41z (flashed with hci_blackbox firmware) is ble controller with k64f as
ble host (flashed with zephyr sample IPSP).
I assume hci_blackbox is not a zephyr based controller is it?

At the other end: Second kw41z (flashed with hci_blackbox firmware) is ble
controller attached to Linux host.

[Kw41z (ble controller)+ k64f (zephyr IPSP)] <---------->[Kw41z (ble
controller)+Linux host]

Issue with testing IPv6 over BLE :

Once the BLE connection is established, within few seconds BLE controller
gets disconnected.
Either zephyr (recent master branch) crashes or BLE controller crashes or
both. Often it is BLE controller that gets disconnected within few
Restarting zephyr might enable establishing the connection once again, but
then ble controller goes down immediately.
Im not sure if will be able to help in case the controller is not
really zephyr based in the other hand we should be able to fix the
host crash if you provide some traces when that happens.

After that, I should disconnect the boards and connect again (via usb
connection) in order to set up the ble connection again.

While on Zephyr side, it always prints connection handle 32
On Linux side, the first time connection handle is 32, afterwards it is
different (handle 65, 128 etc.,) as shown with "hcitool conn".
btmon log shows for specific handle : remote user terminated connection or
connection terminated by local host
I guess with Zephyr the controller crashes and restart using the same
handle, while with Linux it manages to work fine, perhaps this is
because zephyr attempts to use the host flow control?
Luiz Augusto von Dentz

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