BLE Testing functions do not work properly #42534
Description
I am using Nordic nRF5340DK with Zephyr 2.7.0 LTS SDK. I am using built in j-link and SES(Segger Embedded Studio) to debug. I also use emptyapp from nordic on the application core and example HCI uart from /samples/bluetooth/hci_uart and set CONFIG_BT_CTLR_DTM_HCI=y in prj.conf
I am using nrf testing applications like RSSI Viewer and DTM test demos on Windows and code for nRF5340DK is being build in linux Debian enviroment.
The issue:
When I use HCI command LE Transmitter Test the test packets stop transmitting after certain time or packet count(around ~4000).
I cant find any workaround to this issue, yet it is needed for Bluetooth hardware testing.
The DTM sample app from nRF Connect SDK works as expected but they are not compatible with Bluetooth stack.
To Reproduce
Build an Empty Application Core from Nordic, to give control for network core, from their repository.
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/nrf5340/empty_app_core/README.html
Build an HCI-UART application with setting: CONFIG_BT_CTLR_DTM_HCI=y
1.Run SES and load HCI-UART example application to the network core,
2.load empty application core to the network core,
3.connect the UART of nrf5340 to rtt-uart output of NRF5340DK to proceed with attaching HCI-BLE to linux
4. On linux(debian in my case) run as su : btattach -B /dev/ttyACM1 -S 1000000 -P h4 &
5. now open the RSSI Viewer application on another Nordic developement kit and start it to watch the BLE radio spectrum.
6. now on the linux run the hci tool and send command: hcitool -i hci1 cmd 0x08 0x1e 0x02 0x20 0x00 0x00 (HCI_LE_Transmitter_Test
[v2] from specification BLE 5.2 Vol 4, Part E) It should start sending packets with PRBS9 at channel 2 with length of 32 bytes, until issuance of the command hcitool -i hci1 cmd 0x08 0x1f (LE_Test_End)
Expected behavior
The Bluetooth stack should transmit test packets continuously until receiving LE_Test_End command from HCI interface, yet it spontaneously stops transmitting sooner than the command LE_Test_End.
Additional info
The same issue happens when in network core app directly is being called ll_test_tx() function from subsys/bluetooth/controller/ll_sw/nordic/lll/lll_test.c - the packets suddenly stop transmitting after some time.