fix zero wLength request in control request

1 files changed, 7 insertions, 1 deletions

diff --git a/src/device/usbd_control.c b/src/device/usbd_control.c
index 87593d4a7..1ec9b4649 100644
--- a/src/device/usbd_control.c
+++ b/src/device/usbd_control.c
@@ -73,6 +73,10 @@ uint8_t* usbd_get_ctrl_buf(void) {
 
 // Queue ZLP status transaction
 static inline bool status_stage_xact(uint8_t rhport, const tusb_control_request_t* request) {
+  // Always use EDPT_CTRL_IN when control request wLength is zero
+  if (request->wLength==0) {
+    return usbd_edpt_xfer(rhport, EDPT_CTRL_IN, NULL, 0, false);
+  }
   // Opposite to endpoint in Data Phase
   const uint8_t ep_addr = request->bmRequestType_bit.direction ? EDPT_CTRL_OUT : EDPT_CTRL_IN;
   return usbd_edpt_xfer(rhport, ep_addr, NULL, 0, false);
@@ -157,7 +161,9 @@ bool usbd_control_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result,
   (void) result;
 
   // Endpoint Address is opposite to direction bit, this is Status Stage complete event
-  if (tu_edpt_dir(ep_addr) != _ctrl_xfer.request.bmRequestType_bit.direction) {
+  // Control request with zero wLength and IN direction also is Status Stage complete event
+  if ((tu_edpt_dir(ep_addr) != _ctrl_xfer.request.bmRequestType_bit.direction)||
+      (_ctrl_xfer.request.wLength==0&&_ctrl_xfer.request.bmRequestType_bit.direction==TUSB_DIR_IN)) {
     TU_ASSERT(0 == xferred_bytes);
 
     // invoke optional dcd hook if available