For control transfers, compare the transmitted length against the requested length to know if a ZLP needs to happen. (fixes #139)

1 files changed, 11 insertions, 4 deletions

diff --git a/src/device/usbd_control.c b/src/device/usbd_control.c
index 4ec432185..e54d04456 100644
--- a/src/device/usbd_control.c
+++ b/src/device/usbd_control.c
@@ -43,8 +43,9 @@ typedef struct
   tusb_control_request_t request;

 

   void* buffer;

-  uint16_t total_len;

+  uint16_t len;

   uint16_t total_transferred;

+  uint16_t requested_len;

 

   bool (*complete_cb) (uint8_t, tusb_control_request_t const *);

 } usbd_control_xfer_t;

@@ -68,7 +69,7 @@ bool tud_control_status(uint8_t rhport, tusb_control_request_t const * request)
 // Each transaction is up to endpoint0's max packet size

 static bool start_control_data_xact(uint8_t rhport)

 {

-  uint16_t const xact_len = tu_min16(_control_state.total_len - _control_state.total_transferred, CFG_TUD_ENDPOINT0_SIZE);

+  uint16_t const xact_len = tu_min16(_control_state.len - _control_state.total_transferred, CFG_TUD_ENDPOINT0_SIZE);

 

   uint8_t ep_addr = EDPT_CTRL_OUT;

 

@@ -89,10 +90,16 @@ void usbd_control_set_complete_callback( bool (*fp) (uint8_t, tusb_control_reque
 

 bool tud_control_xfer(uint8_t rhport, tusb_control_request_t const * request, void* buffer, uint16_t len)

 {

+  // transmitted length must be <= requested length (USB 2.0 spec: 8.5.3.1 )

+  // FIXME: Should logic be here or in place that calls this function?

+  if(len > request->wLength)

+    len = request->wLength;

+

   _control_state.request = (*request);

   _control_state.buffer = buffer;

-  _control_state.total_len = tu_min16(len, request->wLength);

   _control_state.total_transferred = 0;

+  _control_state.requested_len = request->wLength;

+  _control_state.len = len;

 

   if ( len )

   {

@@ -124,7 +131,7 @@ bool usbd_control_xfer_cb (uint8_t rhport, uint8_t ep_addr, xfer_result_t result
   _control_state.total_transferred += xferred_bytes;

   _control_state.buffer += xferred_bytes;

 

-  if ( _control_state.total_len == _control_state.total_transferred || xferred_bytes < CFG_TUD_ENDOINT0_SIZE )

+  if ( (_control_state.requested_len == _control_state.total_transferred) || xferred_bytes < CFG_TUD_ENDOINT0_SIZE )

   {

     // DATA stage is complete

     bool is_ok = true;