STM32 USB Host Library 学习笔记 (3) USBH_HandleControl()

/**
 * @brief  USBH_HandleControl
 *         Handles the USB control transfer state machine
 * @param  pdev: Selected device
 * @retval Status
 */
USBH_Status USBH_HandleControl(USB_OTG_CORE_HANDLE *pdev, USBH_HOST *phost)
{
    switch (phost->Control.state)
case CTRL_DATA_IN_WAIT:

      URB_Status = HCD_GetURB_State( pdev, phost->Control.hc_num_in );

      /* check is DATA packet transfered successfully */
      if (URB_Status == URB_DONE)
      {
        phost->Control.state = CTRL_STATUS_OUT;
      }

      /* manage error cases*/
      else // add -- only when if (URB_Status != URB_DONE)
      if (URB_Status == URB_STALL)

      {
        /* In stall case, return to previous machine state*/
        phost->gState = phost->gStateBkp;

        phost->Control.state = CTRL_STALLED; // add

        // SETUP DATA ACK : IN : STALL 
      }
}