How to trace function calls in controller code

Hi, I am trying to trace function calls in the stack controller part. I planned to printf some log when a certain function is called and find out the relationship of different functions.

But I notice that there is no logging output under `Mynewt/repos/apache-mynewt-nimble/nimble/controller/src` directory. When I added `MODLOG_DFLT` in functions like `ble_ll_rx_end`, the peripheral failed in connection establishment due to unknown reason (but it worked in `ble_ll_rx_pkt_in`). I wonder whether there is a way to print logging information from the controller part, or how I can trace the function calls at runtime.

Highly appreciate!

Start in Mynewt/repos/apache-mynewt-nimble/nimble/controller/src and compare the logging behavior of ble_ll_rx_end with ble_ll_rx_pkt_in. Investigate how controller runtime logging is configured and why adding MODLOG_DFLT affects connection establishment. Done means documenting a reliable way to trace controller calls without breaking peripheral connections.

Written by the indexing model from the issue text.