diff --git a/tests/test/host/test_enum_task.c b/tests/test/host/test_enum_task.c
index c64a7ce3..43238b06 100644
--- a/tests/test/host/test_enum_task.c
+++ b/tests/test/host/test_enum_task.c
@@ -186,6 +186,7 @@ void test_enum_failed_get_full_dev_desc(void)
 {
   osal_semaphore_wait_StubWithCallback(semaphore_wait_timeout_stub(2));
 
+  hcd_pipe_control_close_ExpectAndReturn(0, TUSB_ERROR_NONE);
   hcd_pipe_control_open_ExpectAndReturn(1, desc_device.bMaxPacketSize0, TUSB_ERROR_NONE);
   tusbh_device_mount_failed_cb_Expect(TUSB_ERROR_USBH_MOUNT_DEVICE_NOT_RESPOND, NULL);
 
@@ -202,6 +203,7 @@ void test_enum_failed_get_9byte_config_desc(void)
 {
   osal_semaphore_wait_StubWithCallback(semaphore_wait_timeout_stub(3));
 
+  hcd_pipe_control_close_ExpectAndReturn(0, TUSB_ERROR_NONE);
   hcd_pipe_control_open_ExpectAndReturn(1, desc_device.bMaxPacketSize0, TUSB_ERROR_NONE);
   tusbh_device_attached_cb_ExpectAndReturn((tusb_descriptor_device_t*) enum_data_buffer, 1);
   tusbh_device_mount_failed_cb_Expect(TUSB_ERROR_USBH_MOUNT_DEVICE_NOT_RESPOND, NULL);
@@ -216,6 +218,7 @@ void test_enum_failed_get_9byte_config_desc(void)
 void test_enum_failed_get_full_config_desc(void)
 {
   osal_semaphore_wait_StubWithCallback(semaphore_wait_timeout_stub(4));
+  hcd_pipe_control_close_ExpectAndReturn(0, TUSB_ERROR_NONE);
   hcd_pipe_control_open_ExpectAndReturn(1, desc_device.bMaxPacketSize0, TUSB_ERROR_NONE);
   tusbh_device_attached_cb_ExpectAndReturn((tusb_descriptor_device_t*) enum_data_buffer, 1);
   tusbh_device_mount_failed_cb_Expect(TUSB_ERROR_USBH_MOUNT_DEVICE_NOT_RESPOND, NULL);
@@ -231,6 +234,7 @@ void class_install_expect(void)
 void test_enum_parse_config_desc(void)
 {
   osal_semaphore_wait_StubWithCallback(semaphore_wait_timeout_stub(5));
+  hcd_pipe_control_close_ExpectAndReturn(0, TUSB_ERROR_NONE);
   hcd_pipe_control_open_ExpectAndReturn(1, desc_device.bMaxPacketSize0, TUSB_ERROR_NONE);
   tusbh_device_attached_cb_ExpectAndReturn((tusb_descriptor_device_t*) enum_data_buffer, 1);
 
@@ -245,6 +249,7 @@ void test_enum_parse_config_desc(void)
 void test_enum_set_configure(void)
 {
   osal_semaphore_wait_StubWithCallback(semaphore_wait_timeout_stub(6));
+  hcd_pipe_control_close_ExpectAndReturn(0, TUSB_ERROR_NONE);
   hcd_pipe_control_open_ExpectAndReturn(1, desc_device.bMaxPacketSize0, TUSB_ERROR_NONE);
   tusbh_device_attached_cb_ExpectAndReturn((tusb_descriptor_device_t*) enum_data_buffer, 1);
   class_install_expect();
diff --git a/tinyusb/host/ehci/ehci.c b/tinyusb/host/ehci/ehci.c
index ee1113d9..1d415981 100644
--- a/tinyusb/host/ehci/ehci.c
+++ b/tinyusb/host/ehci/ehci.c
@@ -274,6 +274,7 @@ pipe_handle_t hcd_pipe_open(uint8_t dev_addr, tusb_descriptor_endpoint_t const *
 {
   pipe_handle_t const null_handle = { .dev_addr = 0, .xfer_type = 0, .index = 0 };
 
+  //------------- find a free queue head -------------//
   uint8_t index=0;
   while( index<EHCI_MAX_QHD && ehci_data.device[dev_addr].qhd[index].used )
   {
@@ -289,16 +290,15 @@ pipe_handle_t hcd_pipe_open(uint8_t dev_addr, tusb_descriptor_endpoint_t const *
 
   if (p_endpoint_desc->bmAttributes.xfer == TUSB_XFER_BULK)
   {
-    //------------- insert to async list -------------//
     // TODO might need to to disable async list first
     list_head = get_async_head(usbh_device_info_pool[dev_addr].core_id);
   }else if (p_endpoint_desc->bmAttributes.xfer == TUSB_XFER_INTERRUPT)
   {
-    //------------- insert to period list -------------//
     // TODO might need to to disable period list first
     list_head = get_period_head(usbh_device_info_pool[dev_addr].core_id);
   }
 
+  //------------- insert to async/period list -------------//
   p_qhd->next = list_head->next;
   list_head->next.address = (uint32_t) p_qhd;
   list_head->next.type = EHCI_QUEUE_ELEMENT_QHD;
diff --git a/tinyusb/host/hcd.h b/tinyusb/host/hcd.h
index d180d1c5..f918ca33 100644
--- a/tinyusb/host/hcd.h
+++ b/tinyusb/host/hcd.h
@@ -77,15 +77,13 @@ void hcd_isr(uint8_t hostid);
 //--------------------------------------------------------------------+
 tusb_error_t  hcd_pipe_control_open(uint8_t dev_addr, uint8_t max_packet_size) ATTR_WARN_UNUSED_RESULT;
 tusb_error_t  hcd_pipe_control_xfer(uint8_t dev_addr, tusb_std_request_t const * p_request, uint8_t data[]) ATTR_WARN_UNUSED_RESULT;
+tusb_error_t  hcd_pipe_control_close(uint8_t dev_addr) ATTR_WARN_UNUSED_RESULT;
+
 pipe_handle_t hcd_pipe_open(uint8_t dev_addr, tusb_descriptor_endpoint_t const * endpoint_desc) ATTR_WARN_UNUSED_RESULT;
+tusb_error_t  hcd_pipe_xfer(pipe_handle_t pipe_hdl, uint8_t buffer[])  ATTR_WARN_UNUSED_RESULT;
+tusb_error_t  hcd_pipe_close(pipe_handle_t pipe_hdl) ATTR_WARN_UNUSED_RESULT;
 
 #if 0
-//tusb_error_t hcd_pipe_open(
-//    uint8_t hostid, uint8_t device_address,
-//
-//    )ATTR_WARN_UNUSED_RESULT;
-tusb_error_t hcd_pipe_close()ATTR_WARN_UNUSED_RESULT;
-tusb_error_t hcd_pipe_transfer()ATTR_WARN_UNUSED_RESULT;
 tusb_error_t hcd_pipe_cancel()ATTR_WARN_UNUSED_RESULT;
 #endif
 
diff --git a/tinyusb/host/usbh.c b/tinyusb/host/usbh.c
index 794074f8..3c2010c0 100644
--- a/tinyusb/host/usbh.c
+++ b/tinyusb/host/usbh.c
@@ -173,12 +173,15 @@ OSAL_TASK_DECLARE(usbh_enumeration_task)
     )
   );
 
-  //------------- update port info & open control pipe for new address -------------//
+  //------------- update port info & close control pipe of addr0 -------------//
   usbh_device_info_pool[new_addr].core_id  = usbh_device_info_pool[0].core_id;
   usbh_device_info_pool[new_addr].hub_addr = usbh_device_info_pool[0].hub_addr;
   usbh_device_info_pool[new_addr].hub_port = usbh_device_info_pool[0].hub_port;
   usbh_device_info_pool[new_addr].speed    = usbh_device_info_pool[0].speed;
   usbh_device_info_pool[new_addr].status   = TUSB_DEVICE_STATUS_ADDRESSED;
+  hcd_pipe_control_close(0);
+
+  // open control pipe for new address
   TASK_ASSERT_STATUS ( hcd_pipe_control_open(new_addr, ((tusb_descriptor_device_t*) enum_data_buffer)->bMaxPacketSize0 ) );
 
   //------------- Get full device descriptor -------------//