diff --git a/bsp/stm32f4xx-HAL/drivers/drv_usbh.c b/bsp/stm32f4xx-HAL/drivers/drv_usbh.c
index 6065e06f8ea01b71b0de4104f151963fabc22421..e002c2f7e66e229cacca9ff608f71dc93bd9679a 100644
--- a/bsp/stm32f4xx-HAL/drivers/drv_usbh.c
+++ b/bsp/stm32f4xx-HAL/drivers/drv_usbh.c
@@ -179,6 +179,9 @@ static int drv_pipe_xfer(upipe_t pipe, rt_uint8_t token, void *buffer, int nbyte
             {
                 pipe->callback(pipe);
             }
+            if (pipe->ep.bEndpointAddress & 0x80) {
+                return HAL_HCD_HC_GetXferCount(&_stm_hhcd_fs, pipe->pipe_index);
+            } 
             return nbytes;
         }
         return -1;