USB CDC ACM + freertos + peer manager + ble connection

Question

Hello,

I made a project based on the usbd_ble_uart_freertos example and added peer manager for secure connections.

It works in a way that someone can open the uart port and send data o r a ble connection can be made if an advertising peripheral is available.

But USB CDC dies after initiating the ble connection: After a ble connection is made my serial app on the pc hangs when opening the com port and I don't see any messages in the debugger.

I know that this is difficult but I don't know which code snippet to post here.

Maybe someone has an idea why initiating an ble connection leads to fail usb cdc acm?

I am using nrf sdk 17.0.1.

A small update: the app itself still works when pc tries to open the UART. BLE devices are found and connected. But USB CDC ACM module seems to be dead? I enabled logging APP_USBD_CDC_ACM_CONFIG_LOG_ENABLED:

<debug> nrf_sdh_freertos: Creating a SoftDevice task.
<debug> nrf_ble_lesc: Initialized nrf_crypto.
<debug> nrf_ble_lesc: Initialized nrf_ble_lesc.
<debug> nrf_ble_lesc: Generating ECC key pair
<info> app: USB power detected
<debug> nrf_sdh_freertos: Enter softdevice_task.
<debug> ble_scan: Added filter on UUID 1
<info> app: START SCAN
<debug> ble_scan: Scanning
<info> app: USB ready

// here PC opens port
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> app: CDC ACM port opened

<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 0, databits: 0, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 0, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0
<info> cdc_acm: REQ_SET_LINE_CODING: baudrate: 115200, databits: 8, format: 0, parity: 0
<info> cdc_acm: REQ_SET_CONTROL_LINE_STATE: 0x0

This log is when no BLE is connected. After ble gets connected no "cdc_acm" logs are added when trying to send, receive data or close the uart on pc.

Thanks!

Andreas

Update 2:

I narrowed it down to following lines:

void usb_new_event_isr_handler(app_usbd_internal_evt_t const *const p_event, bool queued) {
  NRF_LOG_INFO("in %i",p_event->type);
  BaseType_t xHigherPriorityTaskWoken = pdFALSE;
  UNUSED_PARAMETER(p_event);
  UNUSED_PARAMETER(queued);
  ASSERT(m_usbd_thread != NULL);
  /* Release the semaphore */
  vTaskNotifyGiveFromISR(m_usbd_thread, &xHigherPriorityTaskWoken);
  portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
   NRF_LOG_INFO("out");
   NRF_LOG_FLUSH();
}

In the log I see that in is called but not out once ble connection is made:

<info> app: in 8
<info> app: out
<info> app: USB power detected
<debug> nrf_sdh_freertos: Enter softdevice_task.
<debug> ble_scan: Added filter on UUID 1
<info> app: START SCAN
<debug> ble_scan: Scanning
<info> app: in 10
<info> app: out
<info> app: USB ready
<info> app: in 129
<info> app: out
<info> app: in 2 // is this an usb suspend? Why