Port, board and/or hardware

stm32wb55

MicroPython version

master branch, slightly newer than v1.25

Reproduction

On a stm32wb55 based board with the rfcore (WS) firmware blob wiped / damaged.

from bluetooth import BLE
BLE().active(1)

Ends up stuck with tl_ble_wait_resp: timeout repeated on the command line every few seconds.

Expected behaviour

The tl_ble_wait_resp: timeout message is expected due to lack of response from the rfcore, however there is a timeout in C so this should only retry a limited number of times (2 seconds worth) before aborting with a Timeout error:

Observed behaviour

Instead, the tl_ble_wait_resp: timeout message repeats forever. On my application this cannot be ctrl-c interrupted, it reboots after some time only because we have a WDT running.

Additional Information

I've debugged the issue down to the scheduler, specifically the C STATIC_NODES section of it:

In this case the C scheduler is used to run mp_bluetooth_hci_poll(). Due to timeout trying to communicate with hci a ble_hs_reset() gets run on the nimble os_eventq which starts by resetting the hci transport.
That flows through to mp_bluetooth_hci_uart_init() which itself starts the hci polling...

This re-inserts the hci poll function into head of the c schedule linked list meaing it's ready to be run immediately, forming an infinite loop in mp_sched_run_pending()

Code of Conduct

Yes, I agree