midi only use audio 1.0 without IAD

src/class/midi/midi_device.c

@@ -250,15 +250,13 @@ bool midid_open(uint8_t rhport, tusb_desc_interface_t const * p_interface_desc,
     (*p_length) = sizeof(tusb_desc_interface_t);
 
     // Skip over the class specific descriptor.
-    (*p_length) += p_desc[DESC_OFFSET_LEN];
+    (*p_length) += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
     return true;
   }
 
-  if ( AUDIO_SUBCLASS_MIDI_STREAMING != p_interface_desc->bInterfaceSubClass ||
-       p_interface_desc->bInterfaceProtocol != AUDIO_PROTOCOL_V1 ) {
-    return false;
-  }
+  TU_VERIFY(AUDIO_SUBCLASS_MIDI_STREAMING == p_interface_desc->bInterfaceSubClass &&
+            AUDIO_PROTOCOL_V1 == p_interface_desc->bInterfaceProtocol );
 
   // Find available interface
   midid_interface_t * p_midi = NULL;

src/device/usbd.h

@@ -174,14 +174,12 @@ TU_ATTR_WEAK void tud_resume_cb(void);
 //------------- MIDI -------------//
 
 // Length of template descriptor (96 bytes)
-#define TUD_MIDI_DESC_LEN (8 + 9 + 9 + 9 + 7 + 6 + 6 + 9 + 9 + 7 + 5 + 7 + 5)
+#define TUD_MIDI_DESC_LEN (9 + 9 + 9 + 7 + 6 + 6 + 9 + 9 + 7 + 5 + 7 + 5)
 
 // MIDI simple descriptor
 // - 1 Embedded Jack In connected to 1 External Jack Out
 // - 1 Embedded Jack out connected to 1 External Jack In
 #define TUD_MIDI_DESCRIPTOR(_itfnum, _stridx, _epin, _epout, _epsize) \
-  /* Interface Associate */\
-  8, TUSB_DESC_INTERFACE_ASSOCIATION, _itfnum, 2, TUSB_CLASS_AUDIO, 0x00, AUDIO_PROTOCOL_V1, 0,\
   /* Audio Control (AC) Interface */\
   9, TUSB_DESC_INTERFACE, _itfnum, 0, 0, TUSB_CLASS_AUDIO, AUDIO_SUBCLASS_CONTROL, AUDIO_PROTOCOL_V1, _stridx,\
   /* AC Header */\