bt_hci_driver: IPC service instance initialization failed: -12

[Yaxit]

Hello,

On my custom board, after upgrading from NCS version 2.5.1 to 2.6.1, BLE stopped working.

I get immediately the following trace after calling bt_enable(NULL)

[00:00:02.004,913] <err> bt_hci_driver: IPC service instance initialization failed: -12
[00:00:02.004,943] <err> bt_hci_core: HCI driver open failed (-12)
[00:00:02.004,943] <err> ble: Bluetooth init failed
[00:00:02.004,974] <err> main: Failed to initialize BLE

Some hours of research did not help to find a solution, maybe only some hints:

• The error -12 (-ENOMEM) might be a hint that there is some misconfiguration in the network core?
• Can I assume that the network core is running at this point? I would not expect this error otherwise.

My config relative to BLE are:

CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_MAX_CONN=2
CONFIG_BT_DEVICE_NAME="Test"
CONFIG_BT_USER_DATA_LEN_UPDATE=y
CONFIG_BT_USER_PHY_UPDATE=y
CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS=n

# BLE battery service:
CONFIG_BT_BAS=y

# BLE - MUTLISENSOR:
CONFIG_BT_DEVICE_APPEARANCE=1366

# BLE - DIS:
CONFIG_BT_DIS=y
CONFIG_BT_DIS_MODEL="VNS"

# BLE - NRF5340 Child Image:
CONFIG_NCS_INCLUDE_RPMSG_CHILD_IMAGE=y  # still relevant? I get no warning

During build time I see that a child image is actually built, and both domains are flashed.

Any idea/hint? I found very few problems with this specific error around the support forum.

Thank you!