- add tud_cdc_n_ready() though not used

- usbd now change _usbd_dev.cfg_num before calling driver's open()

src/class/cdc/cdc_device.c

@@ -81,11 +81,11 @@ typedef struct {
 CFG_TUD_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
 static tud_cdc_configure_fifo_t _cdcd_fifo_cfg;
 
-static bool _prep_out_transaction (cdcd_interface_t* p_cdc, bool itf_open) {
+static bool _prep_out_transaction (cdcd_interface_t* p_cdc) {
   uint8_t const rhport = 0;
 
   // Skip if usb is not ready yet
-  TU_VERIFY(tud_ready() || itf_open);
+  TU_VERIFY(tud_ready() && p_cdc->ep_out);
 
   uint16_t available = tu_fifo_remaining(&p_cdc->rx_ff);
 
@@ -120,6 +120,10 @@ bool tud_cdc_configure_fifo(tud_cdc_configure_fifo_t const* cfg) {
   return true;
 }
 
+bool tud_cdc_n_ready(uint8_t itf) {
+  return tud_ready() && _cdcd_itf[itf].ep_in != 0 && _cdcd_itf[itf].ep_out != 0;
+}
+
 bool tud_cdc_n_connected(uint8_t itf) {
   // DTR (bit 0) active  is considered as connected
   return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);
@@ -147,7 +151,7 @@ uint32_t tud_cdc_n_available(uint8_t itf) {
 uint32_t tud_cdc_n_read(uint8_t itf, void* buffer, uint32_t bufsize) {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
   uint32_t num_read = tu_fifo_read_n(&p_cdc->rx_ff, buffer, (uint16_t) TU_MIN(bufsize, UINT16_MAX));
-  _prep_out_transaction(p_cdc, false);
+  _prep_out_transaction(p_cdc);
   return num_read;
 }
 
@@ -158,7 +162,7 @@ bool tud_cdc_n_peek(uint8_t itf, uint8_t* chr) {
 void tud_cdc_n_read_flush(uint8_t itf) {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
   tu_fifo_clear(&p_cdc->rx_ff);
-  _prep_out_transaction(p_cdc, false);
+  _prep_out_transaction(p_cdc);
 }
 
 //--------------------------------------------------------------------+
@@ -340,7 +344,7 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
   }
 
   // Prepare for incoming data
-  _prep_out_transaction(p_cdc, true);
+  _prep_out_transaction(p_cdc);
 
   return drv_len;
 }
@@ -449,7 +453,7 @@ bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
     if (tud_cdc_rx_cb && !tu_fifo_empty(&p_cdc->rx_ff)) tud_cdc_rx_cb(itf);
 
     // prepare for OUT transaction
-    _prep_out_transaction(p_cdc, false);
+    _prep_out_transaction(p_cdc);
   }
 
   // Data sent to host, we continue to fetch from tx fifo to send.

src/class/cdc/cdc_device.h

@@ -61,6 +61,9 @@ bool tud_cdc_configure_fifo(tud_cdc_configure_fifo_t const* cfg);
 // Application API (Multiple Ports) i.e. CFG_TUD_CDC > 1
 //--------------------------------------------------------------------+
 
+// Check if interface is ready
+bool tud_cdc_n_ready(uint8_t itf);
+
 // Check if terminal is connected to this port
 bool tud_cdc_n_connected(uint8_t itf);
 
@@ -116,6 +119,11 @@ bool tud_cdc_n_write_clear(uint8_t itf);
 //--------------------------------------------------------------------+
 // Application API (Single Port)
 //--------------------------------------------------------------------+
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_ready(void) {
+  return tud_cdc_n_ready(0);
+}
+
 TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_connected(void) {
   return tud_cdc_n_connected(0);
 }

src/common/tusb_verify.h

@@ -56,8 +56,8 @@
  *   #define TU_VERIFY(cond)                  if(cond) return false;
  *   #define TU_VERIFY(cond,ret)              if(cond) return ret;
  *
- *   #define TU_ASSERT(cond)                  if(cond) {_MESS_FAILED(); TU_BREAKPOINT(), return false;}
- *   #define TU_ASSERT(cond,ret)              if(cond) {_MESS_FAILED(); TU_BREAKPOINT(), return ret;}
+ *   #define TU_ASSERT(cond)                  if(cond) {TU_MESS_FAILED(); TU_BREAKPOINT(), return false;}
+ *   #define TU_ASSERT(cond,ret)              if(cond) {TU_MESS_FAILED(); TU_BREAKPOINT(), return ret;}
  *------------------------------------------------------------------*/
 
 #ifdef __cplusplus
@@ -70,9 +70,9 @@
 
 #if CFG_TUSB_DEBUG
   #include <stdio.h>
-  #define _MESS_FAILED()    tu_printf("%s %d: ASSERT FAILED\r\n", __func__, __LINE__)
+  #define TU_MESS_FAILED()    tu_printf("%s %d: ASSERT FAILED\r\n", __func__, __LINE__)
 #else
-  #define _MESS_FAILED() do {} while (0)
+  #define TU_MESS_FAILED() do {} while (0)
 #endif
 
 // Halt CPU (breakpoint) when hitting error, only apply for Cortex M3, M4, M7, M33. M55
@@ -119,7 +119,7 @@
  *------------------------------------------------------------------*/
 #define TU_ASSERT_DEFINE(_cond, _ret)                                 \
   do {                                                                \
-    if ( !(_cond) ) { _MESS_FAILED(); TU_BREAKPOINT(); return _ret; } \
+    if ( !(_cond) ) { TU_MESS_FAILED(); TU_BREAKPOINT(); return _ret; } \
   } while(0)
 
 #define TU_ASSERT_1ARGS(_cond)         TU_ASSERT_DEFINE(_cond, false)

src/device/usbd.c

@@ -747,17 +747,23 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
               _usbd_dev.speed = speed; // restore speed
             }
 
+            _usbd_dev.cfg_num = cfg_num;
+
             // Handle the new configuration and execute the corresponding callback
             if ( cfg_num ) {
               // switch to new configuration if not zero
-              TU_ASSERT( process_set_config(rhport, cfg_num) );
+              if (!process_set_config(rhport, cfg_num)) {
+                TU_MESS_FAILED();
+                TU_BREAKPOINT();
+                _usbd_dev.cfg_num = 0;
+                return false;
+              }
               if ( tud_mount_cb ) tud_mount_cb();
             } else {
               if ( tud_umount_cb ) tud_umount_cb();
             }
           }
 
-          _usbd_dev.cfg_num = cfg_num;
           tud_control_status(rhport, p_request);
         }
         break;