4 files changed, 13 insertions, 7 deletions
diff --git a/src/device/dcd.h b/src/device/dcd.h
index abd85a70b..46c11ff1c 100644
--- a/src/device/dcd.h
+++ b/src/device/dcd.h
@@ -94,10 +94,16 @@ TU_VERIFY_STATIC(sizeof(dcd_event_t) <= 12, "size is not correct");
  *------------------------------------------------------------------*/
 bool dcd_init       (uint8_t rhport);
 
+// Enable device interrupt
 void dcd_int_enable (uint8_t rhport);
+
+// Disable device interrupt
 void dcd_int_disable(uint8_t rhport);
 
+// Receive Set Address request, mcu port must also include status IN response
 void dcd_set_address(uint8_t rhport, uint8_t dev_addr);
+
+// Receive Set Config request
 void dcd_set_config (uint8_t rhport, uint8_t config_num);
 
 // Get current frame number
@@ -118,15 +124,13 @@ void dcd_event_setup_received(uint8_t rhport, uint8_t const * setup, bool in_isr
 // helper to send transfer complete event
 void dcd_event_xfer_complete (uint8_t rhport, uint8_t ep_addr, uint32_t xferred_bytes, uint8_t result, bool in_isr);
 
-
 /*------------------------------------------------------------------*/
 /* Endpoint API
  *  - open        : Configure endpoint's registers
  *  - xfer        : Submit a transfer. When complete dcd_event_xfer_complete
  *                  must be called to notify the stack
  *  - busy        : Check if endpoint transferring is complete (TODO remove)
- *  - stall       : stall ep. When control endpoint (addr = 0) is stalled,
- *                  both direction (IN & OUT) of control ep must be stalled.
+ *  - stall       : stall endpoint
  *  - clear_stall : clear stall
  *  - stalled     : check if stalled ( TODO remove )
  *------------------------------------------------------------------*/
diff --git a/src/device/usbd.c b/src/device/usbd.c
index 5baea8460..d07c78c13 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -336,8 +336,8 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
     switch ( p_request->bRequest )
     {
       case TUSB_REQ_SET_ADDRESS:
-        // response with status first before changing device address
-        usbd_control_status(rhport, p_request);
+        // DCD must include zero-length status response since depending on mcu,
+        // status could be sent either before or after changing device address
         dcd_set_address(rhport, (uint8_t) p_request->wValue);
         return true; // skip the rest
       break;
diff --git a/src/device/usbd_control.c b/src/device/usbd_control.c
index ae7e894b7..f06c44f02 100644
--- a/src/device/usbd_control.c
+++ b/src/device/usbd_control.c
@@ -74,7 +74,9 @@ void usbd_control_reset (uint8_t rhport)
 
 void usbd_control_stall(uint8_t rhport)
 {
-  dcd_edpt_stall(rhport, 0);
+  // when stalling control endpoint both IN and OUt will be stalled
+  dcd_edpt_stall(rhport, EDPT_CTRL_OUT);
+  dcd_edpt_stall(rhport, EDPT_CTRL_IN);
 }
 
 bool usbd_control_status(uint8_t rhport, tusb_control_request_t const * request)
diff --git a/src/device/usbd_pvt.h b/src/device/usbd_pvt.h
index 06951673f..14f880e76 100644
--- a/src/device/usbd_pvt.h
+++ b/src/device/usbd_pvt.h
@@ -61,7 +61,7 @@ bool usbd_control_xfer(uint8_t rhport, tusb_control_request_t const * request, v
 // Send STATUS (zero length) packet
 bool usbd_control_status(uint8_t rhport, tusb_control_request_t const * request);
 
-// Stall control endpoint until new setup packet arrived
+// Stall control endpoint (both IN and OUT) until new setup packet arrived
 void usbd_control_stall(uint8_t rhport);
 
 /*------------------------------------------------------------------*/