initial transfer failed in open() shouldn't cause the driver open to fail.

src/class/cdc/cdc_device.c

@@ -231,8 +231,6 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
   // Note: 0xFF can be used with RNDIS
   TU_VERIFY(tu_within(CDC_COMM_PROTOCOL_NONE, itf_desc->bInterfaceProtocol, CDC_COMM_PROTOCOL_ATCOMMAND_CDMA), 0);
 
-  uint16_t len = 0;
-
   // Find available interface
   cdcd_interface_t * p_cdc = NULL;
   uint8_t cdc_id;
@@ -249,13 +247,13 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
   //------------- Control Interface -------------//
   p_cdc->itf_num = itf_desc->bInterfaceNumber;
 
+  uint16_t len = sizeof(tusb_desc_interface_t);
   uint8_t const * p_desc = tu_desc_next( itf_desc );
-  len = sizeof(tusb_desc_interface_t);
 
   // Communication Functional Descriptors
   while ( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && len <= max_len )
   {
-    len += tu_desc_len(p_desc);
+    len   += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
   }
 
@@ -266,7 +264,7 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
 
     p_cdc->ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
 
-    len += tu_desc_len(p_desc);
+    len   += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
   }
 
@@ -275,12 +273,13 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
        (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
   {
     // next to endpoint descriptor
+    len   += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
 
     // Open endpoint pair
     TU_ASSERT( usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &p_cdc->ep_out, &p_cdc->ep_in), 0 );
 
-    len += sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
+    len += 2*sizeof(tusb_desc_endpoint_t);
   }
 
   // Prepare for incoming data

src/class/hid/hid_device.c

@@ -196,7 +196,14 @@ uint16_t hidd_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint1
   memcpy(&p_hid->report_desc_len, &(p_hid->hid_descriptor->wReportLength), 2);
 
   // Prepare for output endpoint
-  if (p_hid->ep_out) TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_hid->epout_buf, sizeof(p_hid->epout_buf)), 0);
+  if (p_hid->ep_out)
+  {
+    if ( !usbd_edpt_xfer(rhport, p_hid->ep_out, p_hid->epout_buf, sizeof(p_hid->epout_buf)) )
+    {
+      TU_LOG1_FAILED();
+      TU_BREAKPOINT();
+    }
+  }
 
   return sizeof(tusb_desc_interface_t) + sizeof(tusb_hid_descriptor_hid_t) + desc_itf->bNumEndpoints*sizeof(tusb_desc_endpoint_t);
 }

src/class/midi/midi_device.c

@@ -359,7 +359,11 @@ uint16_t midid_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint
   }
 
   // Prepare for incoming data
-  TU_ASSERT( usbd_edpt_xfer(rhport, p_midi->ep_out, p_midi->epout_buf, CFG_TUD_MIDI_EPSIZE), 0 );
+  if ( !usbd_edpt_xfer(rhport, p_midi->ep_out, p_midi->epout_buf, CFG_TUD_MIDI_EPSIZE) )
+  {
+    TU_LOG1_FAILED();
+    TU_BREAKPOINT();
+  }
 
   return drv_len;
 }

src/class/msc/msc_device.c

@@ -174,7 +174,11 @@ uint16_t mscd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
   TU_ASSERT( usbd_open_edpt_pair(rhport, tu_desc_next(itf_desc), 2, TUSB_XFER_BULK, &p_msc->ep_out, &p_msc->ep_in), 0 );
 
   // Prepare for Command Block Wrapper
-  TU_ASSERT( usbd_edpt_xfer(rhport, p_msc->ep_out, (uint8_t*) &p_msc->cbw, sizeof(msc_cbw_t)), 0 );
+  if ( !usbd_edpt_xfer(rhport, p_msc->ep_out, (uint8_t*) &p_msc->cbw, sizeof(msc_cbw_t)) )
+  {
+    TU_LOG1_FAILED();
+    TU_BREAKPOINT();
+  }
 
   return _MSC_DRIVER_LEN;
 }

src/class/vendor/vendor_device.c

@@ -186,12 +186,15 @@ uint16_t vendord_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, ui
   TU_ASSERT(usbd_open_edpt_pair(rhport, tu_desc_next(itf_desc), 2, TUSB_XFER_BULK, &p_vendor->ep_out, &p_vendor->ep_in), 0);
 
   p_vendor->itf_num = itf_desc->bInterfaceNumber;
-  uint16_t const drv_len = sizeof(tusb_desc_interface_t) + itf_desc->bNumEndpoints*sizeof(tusb_desc_endpoint_t);
 
   // Prepare for incoming data
-  TU_ASSERT(usbd_edpt_xfer(rhport, p_vendor->ep_out, p_vendor->epout_buf, sizeof(p_vendor->epout_buf)), drv_len);
+  if ( !usbd_edpt_xfer(rhport, p_vendor->ep_out, p_vendor->epout_buf, sizeof(p_vendor->epout_buf)) )
+  {
+    TU_LOG1_FAILED();
+    TU_BREAKPOINT();
+  }
 
-  return drv_len;
+  return sizeof(tusb_desc_interface_t) + itf_desc->bNumEndpoints*sizeof(tusb_desc_endpoint_t);
 }
 
 bool vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)

src/common/tusb_common.h

@@ -228,6 +228,7 @@ void tu_print_var(uint8_t const* buf, uint32_t bufsize)
   for(uint32_t i=0; i<bufsize; i++) tu_printf("%02X ", buf[i]);
 }
 
+
 // Log with debug level 1
 #define TU_LOG1               tu_printf
 #define TU_LOG1_MEM           tu_print_mem
@@ -235,6 +236,7 @@ void tu_print_var(uint8_t const* buf, uint32_t bufsize)
 #define TU_LOG1_INT(_x)       tu_printf(#_x " = %ld\n", (uint32_t) (_x) )
 #define TU_LOG1_HEX(_x)       tu_printf(#_x " = %lX\n", (uint32_t) (_x) )
 #define TU_LOG1_LOCATION()    tu_printf("%s: %d:\r\n", __PRETTY_FUNCTION__, __LINE__)
+#define TU_LOG1_FAILED()      tu_printf("%s: %d: Failed\r\n", __PRETTY_FUNCTION__, __LINE__)
 
 // Log with debug level 2
 #if CFG_TUSB_DEBUG > 1
@@ -277,6 +279,7 @@ static inline char const* lookup_find(lookup_table_t const* p_table, uint32_t ke
   #define TU_LOG1_VAR(...)
   #define TU_LOG1_INT(...)
   #define TU_LOG1_HEX(...)
+  #define TU_LOG1_FAILED()
 #endif
 
 #ifndef TU_LOG2