message: guard uninited semaphore use in IRQ
diff: @@ -203,7 +203,9 @@ void OTG_FS_IRQHandler(void)
  // Mask interrupt, and signal processing of interrupt by usb_cmd_thread
  // The thread will re-enable the interrupt when all pending irqs are clear.
  HAL_NVIC_DisableIRQ(OTG_FS_IRQn);
  + if (sem_usb_irq) {
  osSemaphoreRelease(sem_usb_irq);
  + }
  // Bypass interrupt processing here
  return;
  