Merge branch 'master' into port-ft90x

5 files changed, 358 insertions, 163 deletions

diff --git a/src/device/dcd.h b/src/device/dcd.h
index 66767c1fe..c042cc708 100644
--- a/src/device/dcd.h
+++ b/src/device/dcd.h
@@ -106,7 +106,14 @@ typedef struct TU_ATTR_ALIGNED(4)
 void dcd_init       (uint8_t rhport);
 
 // Interrupt Handler
+#if __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wredundant-decls"
+#endif
 void dcd_int_handler(uint8_t rhport);
+#if __GNUC__
+#pragma GCC diagnostic pop
+#endif
 
 // Enable device interrupt
 void dcd_int_enable (uint8_t rhport);
@@ -137,6 +144,11 @@ void dcd_edpt0_status_complete(uint8_t rhport, tusb_control_request_t const * re
 // Configure endpoint's registers according to descriptor
 bool dcd_edpt_open            (uint8_t rhport, tusb_desc_endpoint_t const * desc_ep);
 
+// Close all non-control endpoints, cancel all pending transfers if any.
+// Invoked when switching from a non-zero Configuration by SET_CONFIGURE therefore
+// required for multiple configuration support.
+void dcd_edpt_close_all       (uint8_t rhport);
+
 // Close an endpoint.
 // Since it is weak, caller must TU_ASSERT this function's existence before calling it.
 void dcd_edpt_close           (uint8_t rhport, uint8_t ep_addr) TU_ATTR_WEAK;
@@ -148,7 +160,7 @@ bool dcd_edpt_xfer            (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer
 // This API is optional, may be useful for register-based for transferring data.
 bool dcd_edpt_xfer_fifo       (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes) TU_ATTR_WEAK;
 
-// Stall endpoint
+// Stall endpoint, any queuing transfer should be removed from endpoint
 void dcd_edpt_stall           (uint8_t rhport, uint8_t ep_addr);
 
 // clear stall, data toggle is also reset to DATA0
diff --git a/src/device/dcd_attr.h b/src/device/dcd_attr.h
index 638a17814..c51940573 100644
--- a/src/device/dcd_attr.h
+++ b/src/device/dcd_attr.h
@@ -36,121 +36,167 @@
 // - PORT_HIGHSPEED: mask to indicate which port support highspeed mode, bit0 for port0 and so on.
 
 //------------- NXP -------------//
-#if   TU_CHECK_MCU(LPC11UXX) || TU_CHECK_MCU(LPC13XX) || TU_CHECK_MCU(LPC15XX)
+#if   TU_CHECK_MCU(OPT_MCU_LPC11UXX, OPT_MCU_LPC13XX, OPT_MCU_LPC15XX)
   #define DCD_ATTR_ENDPOINT_MAX   5
 
-#elif TU_CHECK_MCU(LPC175X_6X) || TU_CHECK_MCU(LPC177X_8X) || TU_CHECK_MCU(LPC40XX)
+#elif TU_CHECK_MCU(OPT_MCU_LPC175X_6X, OPT_MCU_LPC177X_8X, OPT_MCU_LPC40XX)
   #define DCD_ATTR_ENDPOINT_MAX   16
 
-#elif TU_CHECK_MCU(LPC18XX) || TU_CHECK_MCU(LPC43XX)
+#elif TU_CHECK_MCU(OPT_MCU_LPC18XX, OPT_MCU_LPC43XX)
   // TODO USB0 has 6, USB1 has 4
+  #define DCD_ATTR_CONTROLLER_CHIPIDEA_HS
   #define DCD_ATTR_ENDPOINT_MAX   6
 
-#elif TU_CHECK_MCU(LPC51UXX)
+#elif TU_CHECK_MCU(OPT_MCU_LPC51UXX)
    #define DCD_ATTR_ENDPOINT_MAX   5
 
-#elif TU_CHECK_MCU(LPC54XXX)
+#elif TU_CHECK_MCU(OPT_MCU_LPC54XXX)
   // TODO USB0 has 5, USB1 has 6
   #define DCD_ATTR_ENDPOINT_MAX   6
 
-#elif TU_CHECK_MCU(LPC55XX)
+#elif TU_CHECK_MCU(OPT_MCU_LPC55XX)
   // TODO USB0 has 5, USB1 has 6
   #define DCD_ATTR_ENDPOINT_MAX   6
 
-#elif TU_CHECK_MCU(MIMXRT10XX)
+#elif TU_CHECK_MCU(OPT_MCU_MIMXRT10XX)
+  #define DCD_ATTR_CONTROLLER_CHIPIDEA_HS
   #define DCD_ATTR_ENDPOINT_MAX   8
 
-#elif TU_CHECK_MCU(MKL25ZXX) || TU_CHECK_MCU(K32L2BXX)
+#elif TU_CHECK_MCU(OPT_MCU_MKL25ZXX, OPT_MCU_K32L2BXX)
+  #define DCD_ATTR_ENDPOINT_MAX   16
+
+#elif TU_CHECK_MCU(OPT_MCU_MM32F327X)
   #define DCD_ATTR_ENDPOINT_MAX   16
 
 //------------- Nordic -------------//
-#elif TU_CHECK_MCU(NRF5X)
+#elif TU_CHECK_MCU(OPT_MCU_NRF5X)
   // 8 CBI + 1 ISO
   #define DCD_ATTR_ENDPOINT_MAX   9
 
 //------------- Microchip -------------//
-#elif TU_CHECK_MCU(SAMD21) || TU_CHECK_MCU(SAMD51) || TU_CHECK_MCU(SAME5X) || \
-      TU_CHECK_MCU(SAMD11) || TU_CHECK_MCU(SAML21) || TU_CHECK_MCU(SAML22)
+#elif TU_CHECK_MCU(OPT_MCU_SAMD21, OPT_MCU_SAMD51, OPT_MCU_SAME5X) || \
+      TU_CHECK_MCU(OPT_MCU_SAMD11, OPT_MCU_SAML21, OPT_MCU_SAML22)
   #define DCD_ATTR_ENDPOINT_MAX   8
 
-#elif TU_CHECK_MCU(SAMG)
+#elif TU_CHECK_MCU(OPT_MCU_SAMG)
   #define DCD_ATTR_ENDPOINT_MAX   6
   #define DCD_ATTR_ENDPOINT_EXCLUSIVE_NUMBER
 
-#elif TU_CHECK_MCU(SAMX7X)
+#elif TU_CHECK_MCU(OPT_MCU_SAMX7X)
   #define DCD_ATTR_ENDPOINT_MAX   10
   #define DCD_ATTR_ENDPOINT_EXCLUSIVE_NUMBER
 
 //------------- ST -------------//
-#elif TU_CHECK_MCU(STM32F0) || TU_CHECK_MCU(STM32F1) || TU_CHECK_MCU(STM32F3) || \
-      TU_CHECK_MCU(STM32L0) || TU_CHECK_MCU(STM32L1) || TU_CHECK_MCU(STM32L4)
-  // F1: F102, F103
-  // L4: L4x2, L4x3
+#elif TU_CHECK_MCU(OPT_MCU_STM32F0)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32F1)
+  #if defined (STM32F105x8) || defined (STM32F105xB) || defined (STM32F105xC) || \
+      defined (STM32F107xB) || defined (STM32F107xC)
+    #define DCD_ATTR_ENDPOINT_MAX   4
+    #define DCD_ATTR_DWC2_STM32
+  #else
+    #define DCD_ATTR_ENDPOINT_MAX   8
+  #endif
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32F2)
+  // FS has 4 ep, HS has 5 ep
+  #define DCD_ATTR_ENDPOINT_MAX   6
+  #define DCD_ATTR_DWC2_STM32
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32F3)
   #define DCD_ATTR_ENDPOINT_MAX   8
 
-#elif TU_CHECK_MCU(STM32F2) || TU_CHECK_MCU(STM32F4) || TU_CHECK_MCU(STM32F3)
-  // F1: F105, F107 only has 4
-  // L4: L4x5, L4x6 has 6
-  // For most mcu, FS has 4, HS has 6
+#elif TU_CHECK_MCU(OPT_MCU_STM32F4)
+  // For most mcu, FS has 4, HS has 6. TODO 446/469/479 HS has 9
   #define DCD_ATTR_ENDPOINT_MAX   6
+  #define DCD_ATTR_DWC2_STM32
 
-#elif TU_CHECK_MCU(STM32F7)
+#elif TU_CHECK_MCU(OPT_MCU_STM32F7)
   // FS has 6, HS has 9
   #define DCD_ATTR_ENDPOINT_MAX   9
+  #define DCD_ATTR_DWC2_STM32
 
-#elif TU_CHECK_MCU(STM32H7)
+#elif TU_CHECK_MCU(OPT_MCU_STM32H7)
   #define DCD_ATTR_ENDPOINT_MAX   9
+  #define DCD_ATTR_DWC2_STM32
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32G4)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32L0, OPT_MCU_STM32L1)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
+#elif TU_CHECK_MCU(OPT_MCU_STM32L4)
+  #if defined (STM32L475xx) || defined (STM32L476xx) ||                          \
+      defined (STM32L485xx) || defined (STM32L486xx) || defined (STM32L496xx) || \
+      defined (STM32L4A6xx) || defined (STM32L4P5xx) || defined (STM32L4Q5xx) || \
+      defined (STM32L4R5xx) || defined (STM32L4R7xx) || defined (STM32L4R9xx) || \
+      defined (STM32L4S5xx) || defined (STM32L4S7xx) || defined (STM32L4S9xx)
+    #define DCD_ATTR_ENDPOINT_MAX   6
+    #define DCD_ATTR_DWC2_STM32
+  #else
+    #define DCD_ATTR_ENDPOINT_MAX   8
+  #endif
 
 //------------- Sony -------------//
-#elif TU_CHECK_MCU(CXD56)
+#elif TU_CHECK_MCU(OPT_MCU_CXD56)
   #define DCD_ATTR_ENDPOINT_MAX   7
   #define DCD_ATTR_ENDPOINT_EXCLUSIVE_NUMBER
 
 //------------- TI -------------//
-#elif TU_CHECK_MCU(MSP430x5xx)
+#elif TU_CHECK_MCU(OPT_MCU_MSP430x5xx)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
+#elif TU_CHECK_MCU(OPT_MCU_MSP432E4, OPT_MCU_TM4C123, OPT_MCU_TM4C129)
   #define DCD_ATTR_ENDPOINT_MAX   8
 
 //------------- ValentyUSB -------------//
-#elif TU_CHECK_MCU(VALENTYUSB_EPTRI)
+#elif TU_CHECK_MCU(OPT_MCU_VALENTYUSB_EPTRI)
   #define DCD_ATTR_ENDPOINT_MAX   16
 
 //------------- Nuvoton -------------//
-#elif TU_CHECK_MCU(NUC121) || TU_CHECK_MCU(NUC126)
+#elif TU_CHECK_MCU(OPT_MCU_NUC121, OPT_MCU_NUC126)
   #define DCD_ATTR_ENDPOINT_MAX   8
 
-#elif TU_CHECK_MCU(NUC120)
+#elif TU_CHECK_MCU(OPT_MCU_NUC120)
   #define DCD_ATTR_ENDPOINT_MAX   6
 
-#elif TU_CHECK_MCU(NUC505)
+#elif TU_CHECK_MCU(OPT_MCU_NUC505)
   #define DCD_ATTR_ENDPOINT_MAX   12
 
 //------------- Espressif -------------//
-#elif TU_CHECK_MCU(ESP32S2) || TU_CHECK_MCU(ESP32S3)
+#elif TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
   #define DCD_ATTR_ENDPOINT_MAX   6
 
 //------------- Dialog -------------//
-#elif TU_CHECK_MCU(DA1469X)
+#elif TU_CHECK_MCU(OPT_MCU_DA1469X)
   #define DCD_ATTR_ENDPOINT_MAX   4
 
 //------------- Raspberry Pi -------------//
-#elif TU_CHECK_MCU(RP2040)
+#elif TU_CHECK_MCU(OPT_MCU_RP2040)
   #define DCD_ATTR_ENDPOINT_MAX   16
 
 //------------- Silabs -------------//
-#elif TU_CHECK_MCU(EFM32GG) || TU_CHECK_MCU(EFM32GG11) || TU_CHECK_MCU(EFM32GG12)
+#elif TU_CHECK_MCU(OPT_MCU_EFM32GG)
   #define DCD_ATTR_ENDPOINT_MAX   7
 
 //------------- Renesas -------------//
-#elif TU_CHECK_MCU(RX63X) || TU_CHECK_MCU(RX65X) || TU_CHECK_MCU(RX72N)
+#elif TU_CHECK_MCU(OPT_MCU_RX63X, OPT_MCU_RX65X, OPT_MCU_RX72N)
   #define DCD_ATTR_ENDPOINT_MAX   10
 
-//#elif TU_CHECK_MCU(MM32F327X)
-//  #define DCD_ATTR_ENDPOINT_MAX not known yet
-
 //------------- GigaDevice -------------//
-#elif TU_CHECK_MCU(GD32VF103)
+#elif TU_CHECK_MCU(OPT_MCU_GD32VF103)
   #define DCD_ATTR_ENDPOINT_MAX   4
 
+//------------- Broadcom -------------//
+#elif TU_CHECK_MCU(OPT_MCU_BCM2711)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
+//------------- Broadcom -------------//
+#elif TU_CHECK_MCU(OPT_MCU_XMC4000)
+  #define DCD_ATTR_ENDPOINT_MAX   8
+
 //------------- BridgeTek -------------//
 #elif TU_CHECK_MCU(FT90X)
   #define DCD_ATTR_ENDPOINT_MAX   8
diff --git a/src/device/usbd.c b/src/device/usbd.c
index e12dafcfd..6a5210b34 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -38,7 +38,7 @@
 //--------------------------------------------------------------------+
 
 // Debug level of USBD
-#define USBD_DBG_LVL   2
+#define USBD_DBG   2
 
 #ifndef CFG_TUD_TASK_QUEUE_SZ
   #define CFG_TUD_TASK_QUEUE_SZ   16
@@ -143,6 +143,18 @@ static usbd_class_driver_t const _usbd_driver[] =
   },
   #endif
 
+  #if CFG_TUD_VIDEO
+  {
+    DRIVER_NAME("VIDEO")
+    .init             = videod_init,
+    .reset            = videod_reset,
+    .open             = videod_open,
+    .control_xfer_cb  = videod_control_xfer_cb,
+    .xfer_cb          = videod_xfer_cb,
+    .sof              = NULL
+  },
+  #endif
+
   #if CFG_TUD_MIDI
   {
     DRIVER_NAME("MIDI")
@@ -203,7 +215,7 @@ static usbd_class_driver_t const _usbd_driver[] =
   },
   #endif
 
-  #if CFG_TUD_NET
+  #if CFG_TUD_ECM_RNDIS || CFG_TUD_NCM
   {
     DRIVER_NAME("NET")
     .init             = netd_init,
@@ -432,19 +444,22 @@ bool tud_init (uint8_t rhport)
   return true;
 }
 
-static void usbd_reset(uint8_t rhport)
+static void configuration_reset(uint8_t rhport)
 {
-  tu_varclr(&_usbd_dev);
+  for ( uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++ )
+  {
+    get_driver(i)->reset(rhport);
+  }
 
+  tu_varclr(&_usbd_dev);
   memset(_usbd_dev.itf2drv, DRVID_INVALID, sizeof(_usbd_dev.itf2drv)); // invalid mapping
   memset(_usbd_dev.ep2drv , DRVID_INVALID, sizeof(_usbd_dev.ep2drv )); // invalid mapping
+}
 
+static void usbd_reset(uint8_t rhport)
+{
+  configuration_reset(rhport);
   usbd_control_reset();
-
-  for ( uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++ )
-  {
-    get_driver(i)->reset(rhport);
-  }
 }
 
 bool tud_task_event_ready(void)
@@ -686,9 +701,29 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
         {
           uint8_t const cfg_num = (uint8_t) p_request->wValue;
 
-          if ( !_usbd_dev.cfg_num && cfg_num ) TU_ASSERT( process_set_config(rhport, cfg_num) );
-          _usbd_dev.cfg_num = cfg_num;
+          // Only process if new configure is different
+          if (_usbd_dev.cfg_num != cfg_num)
+          {
+            if ( _usbd_dev.cfg_num )
+            {
+              // already configured: need to clear all endpoints and driver first
+              TU_LOG(USBD_DBG, "  Clear current Configuration (%u) before switching\r\n", _usbd_dev.cfg_num);
+
+              // close all non-control endpoints, cancel all pending transfers if any
+              dcd_edpt_close_all(rhport);
 
+              // close all drivers and current configured state except bus speed
+              uint8_t const speed = _usbd_dev.speed;
+              configuration_reset(rhport);
+
+              _usbd_dev.speed = speed; // restore speed
+            }
+
+            // switch to new configuration if not zero
+            if ( cfg_num ) TU_ASSERT( process_set_config(rhport, cfg_num) );
+          }
+
+          _usbd_dev.cfg_num = cfg_num;
           tud_control_status(rhport, p_request);
         }
         break;
@@ -701,7 +736,7 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
           // Only support remote wakeup for device feature
           TU_VERIFY(TUSB_REQ_FEATURE_REMOTE_WAKEUP == p_request->wValue);
 
-          TU_LOG(USBD_DBG_LVL, "    Enable Remote Wakeup\r\n");
+          TU_LOG(USBD_DBG, "    Enable Remote Wakeup\r\n");
 
           // Host may enable remote wake up before suspending especially HID device
           _usbd_dev.remote_wakeup_en = true;
@@ -712,7 +747,7 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
           // Only support remote wakeup for device feature
           TU_VERIFY(TUSB_REQ_FEATURE_REMOTE_WAKEUP == p_request->wValue);
 
-          TU_LOG(USBD_DBG_LVL, "    Disable Remote Wakeup\r\n");
+          TU_LOG(USBD_DBG, "    Disable Remote Wakeup\r\n");
 
           // Host may disable remote wake up after resuming
           _usbd_dev.remote_wakeup_en = false;
@@ -751,16 +786,24 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
         // driver doesn't use alternate settings or implement this
         TU_VERIFY(TUSB_REQ_TYPE_STANDARD == p_request->bmRequestType_bit.type);
 
-        if (TUSB_REQ_GET_INTERFACE == p_request->bRequest)
+        switch(p_request->bRequest)
         {
-          uint8_t alternate = 0;
-          tud_control_xfer(rhport, p_request, &alternate, 1);
-        }else if (TUSB_REQ_SET_INTERFACE == p_request->bRequest)
-        {
-          tud_control_status(rhport, p_request);
-        } else
-        {
-          return false;
+          case TUSB_REQ_GET_INTERFACE:
+          case TUSB_REQ_SET_INTERFACE:
+            // Clear complete callback if driver set since it can also stall the request.
+            usbd_control_set_complete_callback(NULL);
+
+            if (TUSB_REQ_GET_INTERFACE == p_request->bRequest)
+            {
+              uint8_t alternate = 0;
+              tud_control_xfer(rhport, p_request, &alternate, 1);
+            }else
+            {
+              tud_control_status(rhport, p_request);
+            }
+          break;
+
+          default: return false;
         }
       }
     }
@@ -843,12 +886,13 @@ static bool process_control_request(uint8_t rhport, tusb_control_request_t const
 // This function parse configuration descriptor & open drivers accordingly
 static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
 {
-  tusb_desc_configuration_t const * desc_cfg = (tusb_desc_configuration_t const *) tud_descriptor_configuration_cb(cfg_num-1); // index is cfg_num-1
+  // index is cfg_num-1
+  tusb_desc_configuration_t const * desc_cfg = (tusb_desc_configuration_t const *) tud_descriptor_configuration_cb(cfg_num-1);
   TU_ASSERT(desc_cfg != NULL && desc_cfg->bDescriptorType == TUSB_DESC_CONFIGURATION);
 
   // Parse configuration descriptor
   _usbd_dev.remote_wakeup_support = (desc_cfg->bmAttributes & TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP) ? 1 : 0;
-  _usbd_dev.self_powered = (desc_cfg->bmAttributes & TUSB_DESC_CONFIG_ATT_SELF_POWERED) ? 1 : 0;
+  _usbd_dev.self_powered          = (desc_cfg->bmAttributes & TUSB_DESC_CONFIG_ATT_SELF_POWERED ) ? 1 : 0;
 
   // Parse interface descriptor
   uint8_t const * p_desc   = ((uint8_t const*) desc_cfg) + sizeof(tusb_desc_configuration_t);
@@ -856,66 +900,75 @@ static bool process_set_config(uint8_t rhport, uint8_t cfg_num)
 
   while( p_desc < desc_end )
   {
-    tusb_desc_interface_assoc_t const * desc_iad = NULL;
+    uint8_t assoc_itf_count = 1;
 
     // Class will always starts with Interface Association (if any) and then Interface descriptor
     if ( TUSB_DESC_INTERFACE_ASSOCIATION == tu_desc_type(p_desc) )
     {
-      desc_iad = (tusb_desc_interface_assoc_t const *) p_desc;
+      tusb_desc_interface_assoc_t const * desc_iad = (tusb_desc_interface_assoc_t const *) p_desc;
+      assoc_itf_count = desc_iad->bInterfaceCount;
+
       p_desc = tu_desc_next(p_desc); // next to Interface
+
+      // IAD's first interface number and class should match with opened interface
+      //TU_ASSERT(desc_iad->bFirstInterface == desc_itf->bInterfaceNumber &&
+      //          desc_iad->bFunctionClass  == desc_itf->bInterfaceClass);
     }
 
     TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
-
     tusb_desc_interface_t const * desc_itf = (tusb_desc_interface_t const*) p_desc;
-    uint16_t const remaining_len = desc_end-p_desc;
-
-    // Interface number must not be used already
-    TU_ASSERT(DRVID_INVALID == _usbd_dev.itf2drv[desc_itf->bInterfaceNumber]);
-
-    // TODO usbd can calculate the total length used for driver --> driver open() does not need to calculate it
-    // uint16_t const drv_len = tu_desc_get_interface_total_len(desc_itf, desc_iad ? desc_iad->bInterfaceCount : 1, desc_end-p_desc);
 
     // Find driver for this interface
+    uint16_t const remaining_len = desc_end-p_desc;
     uint8_t drv_id;
     for (drv_id = 0; drv_id < TOTAL_DRIVER_COUNT; drv_id++)
     {
       usbd_class_driver_t const *driver = get_driver(drv_id);
       uint16_t const drv_len = driver->open(rhport, desc_itf, remaining_len);
 
-      if ( drv_len > 0 )
+      if ( (sizeof(tusb_desc_interface_t) <= drv_len)  && (drv_len <= remaining_len) )
       {
-        // Open successfully, check if length is correct
-        TU_ASSERT( sizeof(tusb_desc_interface_t) <= drv_len && drv_len <= remaining_len);
-
+        // Open successfully
         TU_LOG2("  %s opened\r\n", driver->name);
 
-        // bind interface to found driver
-        _usbd_dev.itf2drv[desc_itf->bInterfaceNumber] = drv_id;
+        // Some drivers use 2 or more interfaces but may not have IAD e.g MIDI (always) or
+        // BTH (even CDC) with class in device descriptor (single interface)
+        if ( assoc_itf_count == 1)
+        {
+          #if CFG_TUD_CDC
+          if ( driver->open == cdcd_open ) assoc_itf_count = 2;
+          #endif
 
-        // If using IAD, bind all interfaces to the same driver
-        if (desc_iad)
+          #if CFG_TUD_MIDI
+          if ( driver->open == midid_open ) assoc_itf_count = 2;
+          #endif
+
+          #if CFG_TUD_BTH && CFG_TUD_BTH_ISO_ALT_COUNT
+          if ( driver->open == btd_open ) assoc_itf_count = 2;
+          #endif
+        }
+
+        // bind (associated) interfaces to found driver
+        for(uint8_t i=0; i<assoc_itf_count; i++)
         {
-          // IAD's first interface number and class should match with opened interface
-          TU_ASSERT(desc_iad->bFirstInterface == desc_itf->bInterfaceNumber &&
-                    desc_iad->bFunctionClass  == desc_itf->bInterfaceClass);
+          uint8_t const itf_num = desc_itf->bInterfaceNumber+i;
 
-          for(uint8_t i=1; i<desc_iad->bInterfaceCount; i++)
-          {
-            _usbd_dev.itf2drv[desc_itf->bInterfaceNumber+i] = drv_id;
-          }
+          // Interface number must not be used already
+          TU_ASSERT(DRVID_INVALID == _usbd_dev.itf2drv[itf_num]);
+          _usbd_dev.itf2drv[itf_num] = drv_id;
         }
 
         // bind all endpoints to found driver
         tu_edpt_bind_driver(_usbd_dev.ep2drv, desc_itf, drv_len, drv_id);
 
-        p_desc += drv_len; // next interface
+        // next Interface
+        p_desc += drv_len;
 
         break; // exit driver find loop
       }
     }
 
-    // Failed if cannot find supported driver
+    // Failed if there is no supported drivers
     TU_ASSERT(drv_id < TOTAL_DRIVER_COUNT);
   }
 
@@ -937,19 +990,23 @@ static bool process_get_descriptor(uint8_t rhport, tusb_control_request_t const
     {
       TU_LOG2(" Device\r\n");
 
-      uint16_t len = sizeof(tusb_desc_device_t);
+      void* desc_device = (void*) (uintptr_t) tud_descriptor_device_cb();
 
-      // Only send up to EP0 Packet Size if not addressed
+      // Only response with exactly 1 Packet if: not addressed and host requested more data than device descriptor has.
       // This only happens with the very first get device descriptor and EP0 size = 8 or 16.
-      if ((CFG_TUD_ENDPOINT0_SIZE < sizeof(tusb_desc_device_t)) && !_usbd_dev.addressed)
+      if ((CFG_TUD_ENDPOINT0_SIZE < sizeof(tusb_desc_device_t)) && !_usbd_dev.addressed &&
+          ((tusb_control_request_t const*) p_request)->wLength > sizeof(tusb_desc_device_t))
       {
-        len = CFG_TUD_ENDPOINT0_SIZE;
-
         // Hack here: we modify the request length to prevent usbd_control response with zlp
-        ((tusb_control_request_t*) p_request)->wLength = CFG_TUD_ENDPOINT0_SIZE;
-      }
+        // since we are responding with 1 packet & less data than wLength.
+        tusb_control_request_t mod_request = *p_request;
+        mod_request.wLength = CFG_TUD_ENDPOINT0_SIZE;
 
-      return tud_control_xfer(rhport, p_request, (void*) tud_descriptor_device_cb(), len);
+        return tud_control_xfer(rhport, &mod_request, desc_device, CFG_TUD_ENDPOINT0_SIZE);
+      }else
+      {
+        return tud_control_xfer(rhport, p_request, desc_device, sizeof(tusb_desc_device_t));
+      }
     }
     break;
 
@@ -960,24 +1017,37 @@ static bool process_get_descriptor(uint8_t rhport, tusb_control_request_t const
       // requested by host if USB > 2.0 ( i.e 2.1 or 3.x )
       if (!tud_descriptor_bos_cb) return false;
 
-      tusb_desc_bos_t const* desc_bos = (tusb_desc_bos_t const*) tud_descriptor_bos_cb();
+      uintptr_t desc_bos = (uintptr_t) tud_descriptor_bos_cb();
+      TU_ASSERT(desc_bos);
 
       // Use offsetof to avoid pointer to the odd/misaligned address
-      uint16_t const total_len = tu_le16toh( tu_unaligned_read16((uint8_t*) desc_bos + offsetof(tusb_desc_bos_t, wTotalLength)) );
+      uint16_t const total_len = tu_le16toh( tu_unaligned_read16((const void*) (desc_bos + offsetof(tusb_desc_bos_t, wTotalLength))) );
 
       return tud_control_xfer(rhport, p_request, (void*) desc_bos, total_len);
     }
     break;
 
     case TUSB_DESC_CONFIGURATION:
+    case TUSB_DESC_OTHER_SPEED_CONFIG:
     {
-      TU_LOG2(" Configuration[%u]\r\n", desc_index);
+      uintptr_t desc_config;
+
+      if ( desc_type == TUSB_DESC_CONFIGURATION )
+      {
+        TU_LOG2(" Configuration[%u]\r\n", desc_index);
+        desc_config = (uintptr_t) tud_descriptor_configuration_cb(desc_index);
+      }else
+      {
+        // Host only request this after getting Device Qualifier descriptor
+        TU_LOG2(" Other Speed Configuration\r\n");
+        TU_VERIFY( tud_descriptor_other_speed_configuration_cb );
+        desc_config = (uintptr_t) tud_descriptor_other_speed_configuration_cb(desc_index);
+      }
 
-      tusb_desc_configuration_t const* desc_config = (tusb_desc_configuration_t const*) tud_descriptor_configuration_cb(desc_index);
       TU_ASSERT(desc_config);
 
       // Use offsetof to avoid pointer to the odd/misaligned address
-      uint16_t const total_len = tu_le16toh( tu_unaligned_read16((uint8_t*) desc_config + offsetof(tusb_desc_configuration_t, wTotalLength)) );
+      uint16_t const total_len = tu_le16toh( tu_unaligned_read16((const void*) (desc_config + offsetof(tusb_desc_configuration_t, wTotalLength))) );
 
       return tud_control_xfer(rhport, p_request, (void*) desc_config, total_len);
     }
@@ -988,38 +1058,26 @@ static bool process_get_descriptor(uint8_t rhport, tusb_control_request_t const
       TU_LOG2(" String[%u]\r\n", desc_index);
 
       // String Descriptor always uses the desc set from user
-      uint8_t const* desc_str = (uint8_t const*) tud_descriptor_string_cb(desc_index, p_request->wIndex);
+      uint8_t const* desc_str = (uint8_t const*) tud_descriptor_string_cb(desc_index, tu_le16toh(p_request->wIndex));
       TU_VERIFY(desc_str);
 
       // first byte of descriptor is its size
-      return tud_control_xfer(rhport, p_request, (void*) desc_str, desc_str[0]);
+      return tud_control_xfer(rhport, p_request, (void*) (uintptr_t) desc_str, tu_desc_len(desc_str));
     }
     break;
 
     case TUSB_DESC_DEVICE_QUALIFIER:
+    {
       TU_LOG2(" Device Qualifier\r\n");
 
-      // Host sends this request to ask why our device with USB BCD from 2.0
-      // but is running at Full/Low Speed. If not highspeed capable stall this request,
-      // otherwise return the descriptor that could work in highspeed mode
-      if ( tud_descriptor_device_qualifier_cb )
-      {
-        uint8_t const* desc_qualifier = tud_descriptor_device_qualifier_cb();
-        TU_ASSERT(desc_qualifier);
+      TU_VERIFY( tud_descriptor_device_qualifier_cb );
 
-        // first byte of descriptor is its size
-        return tud_control_xfer(rhport, p_request, (void*) desc_qualifier, desc_qualifier[0]);
-      }else
-      {
-        return false;
-      }
-    break;
+      uint8_t const* desc_qualifier = tud_descriptor_device_qualifier_cb();
+      TU_VERIFY(desc_qualifier);
 
-    case TUSB_DESC_OTHER_SPEED_CONFIG:
-      TU_LOG2(" Other Speed Configuration\r\n");
-
-      // After Device Qualifier descriptor is received host will ask for this descriptor
-      return false; // not supported
+      // first byte of descriptor is its size
+      return tud_control_xfer(rhport, p_request, (void*) (uintptr_t) desc_qualifier, tu_desc_len(desc_qualifier));
+    }
     break;
 
     default: return false;
@@ -1034,15 +1092,11 @@ void dcd_event_handler(dcd_event_t const * event, bool in_isr)
   switch (event->event_id)
   {
     case DCD_EVENT_UNPLUGGED:
-      // UNPLUGGED event can be bouncing, only processing if we are currently connected
-      if ( _usbd_dev.connected )
-      {
-        _usbd_dev.connected  = 0;
-        _usbd_dev.addressed  = 0;
-        _usbd_dev.cfg_num    = 0;
-        _usbd_dev.suspended  = 0;
-        osal_queue_send(_usbd_q, event, in_isr);
-      }
+      _usbd_dev.connected  = 0;
+      _usbd_dev.addressed  = 0;
+      _usbd_dev.cfg_num    = 0;
+      _usbd_dev.suspended  = 0;
+      osal_queue_send(_usbd_q, event, in_isr);
     break;
 
     case DCD_EVENT_SUSPEND:
@@ -1301,27 +1355,33 @@ bool usbd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
 
 void usbd_edpt_stall(uint8_t rhport, uint8_t ep_addr)
 {
-  TU_LOG(USBD_DBG_LVL, "    Stall EP %02X", ep_addr);
 
   uint8_t const epnum = tu_edpt_number(ep_addr);
   uint8_t const dir   = tu_edpt_dir(ep_addr);
 
-  dcd_edpt_stall(rhport, ep_addr);
-  _usbd_dev.ep_status[epnum][dir].stalled = true;
-  _usbd_dev.ep_status[epnum][dir].busy = true;
+  // only stalled if currently cleared
+  if ( !_usbd_dev.ep_status[epnum][dir].stalled )
+  {
+    TU_LOG(USBD_DBG, "    Stall EP %02X\r\n", ep_addr);
+    dcd_edpt_stall(rhport, ep_addr);
+    _usbd_dev.ep_status[epnum][dir].stalled = true;
+    _usbd_dev.ep_status[epnum][dir].busy = true;
+  }
 }
 
 void usbd_edpt_clear_stall(uint8_t rhport, uint8_t ep_addr)
 {
-  TU_LOG(USBD_DBG_LVL, "    Clear Stall EP %02X", ep_addr);
-
   uint8_t const epnum = tu_edpt_number(ep_addr);
   uint8_t const dir   = tu_edpt_dir(ep_addr);
 
-
-  dcd_edpt_clear_stall(rhport, ep_addr);
-  _usbd_dev.ep_status[epnum][dir].stalled = false;
-  _usbd_dev.ep_status[epnum][dir].busy = false;
+  // only clear if currently stalled
+  if ( _usbd_dev.ep_status[epnum][dir].stalled )
+  {
+    TU_LOG(USBD_DBG, "    Clear Stall EP %02X\r\n", ep_addr);
+    dcd_edpt_clear_stall(rhport, ep_addr);
+    _usbd_dev.ep_status[epnum][dir].stalled = false;
+    _usbd_dev.ep_status[epnum][dir].busy = false;
+  }
 }
 
 bool usbd_edpt_stalled(uint8_t rhport, uint8_t ep_addr)
@@ -1345,7 +1405,13 @@ void usbd_edpt_close(uint8_t rhport, uint8_t ep_addr)
   TU_ASSERT(dcd_edpt_close, /**/);
   TU_LOG2("  CLOSING Endpoint: 0x%02X\r\n", ep_addr);
 
+  uint8_t const epnum = tu_edpt_number(ep_addr);
+  uint8_t const dir   = tu_edpt_dir(ep_addr);
+
   dcd_edpt_close(rhport, ep_addr);
+  _usbd_dev.ep_status[epnum][dir].stalled = false;
+  _usbd_dev.ep_status[epnum][dir].busy = false;
+  _usbd_dev.ep_status[epnum][dir].claimed = false;
 
   return;
 }
diff --git a/src/device/usbd.h b/src/device/usbd.h
index 9becf2d0d..ec34817fa 100644
--- a/src/device/usbd.h
+++ b/src/device/usbd.h
@@ -113,9 +113,16 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid);
 TU_ATTR_WEAK uint8_t const * tud_descriptor_bos_cb(void);
 
 // Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
-// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
 TU_ATTR_WEAK uint8_t const* tud_descriptor_device_qualifier_cb(void);
 
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+TU_ATTR_WEAK uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index);
+
 // Invoked when device is mounted (configured)
 TU_ATTR_WEAK void tud_mount_cb(void);
 
@@ -171,17 +178,18 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   0x9C, 0xD2, 0x65, 0x9D, 0x9E, 0x64, 0x8A, 0x9F
 
 //--------------------------------------------------------------------+
-// Configuration & Interface Descriptor Templates
+// Configuration Descriptor Templates
 //--------------------------------------------------------------------+
 
-//------------- Configuration -------------//
 #define TUD_CONFIG_DESC_LEN   (9)
 
 // Config number, interface count, string index, total length, attribute, power in mA
 #define TUD_CONFIG_DESCRIPTOR(config_num, _itfcount, _stridx, _total_len, _attribute, _power_ma) \
   9, TUSB_DESC_CONFIGURATION, U16_TO_U8S_LE(_total_len), _itfcount, config_num, _stridx, TU_BIT(7) | _attribute, (_power_ma)/2
 
-//------------- CDC -------------//
+//--------------------------------------------------------------------+
+// CDC Descriptor Templates
+//--------------------------------------------------------------------+
 
 // Length of template descriptor: 66 bytes
 #define TUD_CDC_DESC_LEN  (8+9+5+5+4+5+7+9+7+7)
@@ -210,7 +218,9 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint In */\
   7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
 
-//------------- MSC -------------//
+//--------------------------------------------------------------------+
+// MSC Descriptor Templates
+//--------------------------------------------------------------------+
 
 // Length of template descriptor: 23 bytes
 #define TUD_MSC_DESC_LEN    (9 + 7 + 7)
@@ -224,7 +234,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint In */\
   7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
 
-//------------- HID -------------//
+
+//--------------------------------------------------------------------+
+// HID Descriptor Templates
+//--------------------------------------------------------------------+
 
 // Length of template descriptor: 25 bytes
 #define TUD_HID_DESC_LEN    (9 + 9 + 7)
@@ -254,8 +267,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint In */\
   7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_epsize), _ep_interval
 
-//------------- MIDI -------------//
-// MIDI v1.0 is based on Audio v1.0
+//--------------------------------------------------------------------+
+// MIDI Descriptor Templates
+// Note: MIDI v1.0 is based on Audio v1.0
+//--------------------------------------------------------------------+
 
 #define TUD_MIDI_DESC_HEAD_LEN (9 + 9 + 9 + 7)
 #define TUD_MIDI_DESC_HEAD(_itfnum,  _stridx, _numcables) \
@@ -312,7 +327,9 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   TUD_MIDI_DESC_EP(_epin, _epsize, 1),\
   TUD_MIDI_JACKID_OUT_EMB(1)
 
-//------------- AUDIO -------------//
+//--------------------------------------------------------------------+
+// Audio v2.0 Descriptor Templates
+//--------------------------------------------------------------------+
 
 /* Standard Interface Association Descriptor (IAD) */
 #define TUD_AUDIO_DESC_IAD_LEN 8
@@ -544,7 +561,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
     ((((_maxFrequency + ((CFG_TUSB_RHPORT0_MODE & OPT_MODE_HIGH_SPEED) ? 7999 : 999)) / ((CFG_TUSB_RHPORT0_MODE & OPT_MODE_HIGH_SPEED) ? 8000 : 1000)) + 1) * _nBytesPerSample * _nChannels)
 
 
-//------------- TUD_USBTMC/USB488 -------------//
+//--------------------------------------------------------------------+
+// USBTMC/USB488 Descriptor Templates
+//--------------------------------------------------------------------+
+
 #define TUD_USBTMC_APP_CLASS    (TUSB_CLASS_APPLICATION_SPECIFIC)
 #define TUD_USBTMC_APP_SUBCLASS 0x03u
 
@@ -574,8 +594,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 
 #define TUD_USBTMC_INT_DESCRIPTOR_LEN (7u)
 
+//--------------------------------------------------------------------+
+// Vendor Descriptor Templates
+//--------------------------------------------------------------------+
 
-//------------- Vendor -------------//
 #define TUD_VENDOR_DESC_LEN  (9+7+7)
 
 // Interface number, string index, EP Out & IN address, EP size
@@ -587,7 +609,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint In */\
   7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
 
-//------------- DFU Runtime -------------//
+//--------------------------------------------------------------------+
+// DFU Runtime Descriptor Templates
+//--------------------------------------------------------------------+
+
 #define TUD_DFU_APP_CLASS    (TUSB_CLASS_APPLICATION_SPECIFIC)
 #define TUD_DFU_APP_SUBCLASS (APP_SUBCLASS_DFU_RUNTIME)
 
@@ -602,6 +627,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Function */ \
   9, DFU_DESC_FUNCTIONAL, _attr, U16_TO_U8S_LE(_timeout), U16_TO_U8S_LE(_xfer_size), U16_TO_U8S_LE(0x0101)
 
+//--------------------------------------------------------------------+
+// DFU Descriptor Templates
+//--------------------------------------------------------------------+
+
 // Length of template descriptor: 9 bytes + number of alternatives * 9
 #define TUD_DFU_DESC_LEN(_alt_count)    (9 + (_alt_count) * 9)
 
@@ -647,8 +676,9 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
   _TUD_DFU_ALT_7(_itfnum, _alt_count+1, _stridx+1)
 
-
-//------------- CDC-ECM -------------//
+//--------------------------------------------------------------------+
+// CDC-ECM Descriptor Templates
+//--------------------------------------------------------------------+
 
 // Length of template descriptor: 71 bytes
 #define TUD_CDC_ECM_DESC_LEN  (8+9+5+5+13+7+9+9+7+7)
@@ -677,8 +707,9 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint Out */\
   7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
 
-
-//------------- RNDIS -------------//
+//--------------------------------------------------------------------+
+// RNDIS Descriptor Templates
+//--------------------------------------------------------------------+
 
 #if 0
 /* Windows XP */
@@ -719,7 +750,10 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Endpoint Out */\
   7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
 
-//------------- BT Radio -------------//
+//--------------------------------------------------------------------+
+// Bluetooth Radio Descriptor Templates
+//--------------------------------------------------------------------+
+
 #define TUD_BT_APP_CLASS                    (TUSB_CLASS_WIRELESS_CONTROLLER)
 #define TUD_BT_APP_SUBCLASS                 0x01
 #define TUD_BT_PROTOCOL_PRIMARY_CONTROLLER  0x01
@@ -729,8 +763,8 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 #define CFG_TUD_BTH_ISO_ALT_COUNT 0
 #endif
 
-// Length of template descriptor: 30 bytes + number of ISO alternatives * 23
-#define TUD_BTH_DESC_LEN (9 + 7 + 7 + 7 + (CFG_TUD_BTH_ISO_ALT_COUNT) * (9 + 7 + 7))
+// Length of template descriptor: 38 bytes + number of ISO alternatives * 23
+#define TUD_BTH_DESC_LEN (8 + 9 + 7 + 7 + 7 + (CFG_TUD_BTH_ISO_ALT_COUNT) * (9 + 7 + 7))
 
 /* Primary Interface */
 #define TUD_BTH_PRI_ITF(_itfnum, _stridx, _ep_evt, _ep_evt_size, _ep_evt_interval, _ep_in, _ep_out, _ep_size) \
@@ -770,10 +804,46 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 
 // BT Primary controller descriptor
 // Interface number, string index, attributes, event endpoint, event endpoint size, interval, data in, data out, data endpoint size, iso endpoint sizes
+// TODO BTH should also use IAD like CDC for composite device
 #define TUD_BTH_DESCRIPTOR(_itfnum, _stridx, _ep_evt, _ep_evt_size, _ep_evt_interval, _ep_in, _ep_out, _ep_size,...) \
+  /* Interface Associate */\
+  8, TUSB_DESC_INTERFACE_ASSOCIATION, _itfnum, 2, TUD_BT_APP_CLASS, TUD_BT_APP_SUBCLASS, TUD_BT_PROTOCOL_PRIMARY_CONTROLLER, 0,\
   TUD_BTH_PRI_ITF(_itfnum, _stridx, _ep_evt, _ep_evt_size, _ep_evt_interval, _ep_in, _ep_out, _ep_size) \
   TUD_BTH_ISO_ITFS(_itfnum + 1, _ep_in + 1, _ep_out + 1, __VA_ARGS__)
 
+//--------------------------------------------------------------------+
+// CDC-NCM Descriptor Templates
+//--------------------------------------------------------------------+
+
+// Length of template descriptor
+#define TUD_CDC_NCM_DESC_LEN  (8+9+5+5+13+6+7+9+9+7+7)
+
+// CDC-ECM Descriptor Template
+// Interface number, description string index, MAC address string index, EP notification address and size, EP data address (out, in), and size, max segment size.
+#define TUD_CDC_NCM_DESCRIPTOR(_itfnum, _desc_stridx, _mac_stridx, _ep_notif, _ep_notif_size, _epout, _epin, _epsize, _maxsegmentsize) \
+  /* Interface Association */\
+  8, TUSB_DESC_INTERFACE_ASSOCIATION, _itfnum, 2, TUSB_CLASS_CDC, CDC_COMM_SUBCLASS_NETWORK_CONTROL_MODEL, 0, 0,\
+  /* CDC Control Interface */\
+  9, TUSB_DESC_INTERFACE, _itfnum, 0, 1, TUSB_CLASS_CDC, CDC_COMM_SUBCLASS_NETWORK_CONTROL_MODEL, 0, _desc_stridx,\
+  /* CDC-NCM Header */\
+  5, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_HEADER, U16_TO_U8S_LE(0x0110),\
+  /* CDC-NCM Union */\
+  5, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_UNION, _itfnum, (uint8_t)((_itfnum) + 1),\
+  /* CDC-NCM Functional Descriptor */\
+  13, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_ETHERNET_NETWORKING, _mac_stridx, 0, 0, 0, 0, U16_TO_U8S_LE(_maxsegmentsize), U16_TO_U8S_LE(0), 0, \
+  /* CDC-NCM Functional Descriptor */\
+  6, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_NCM, U16_TO_U8S_LE(0x0100), 0, \
+  /* Endpoint Notification */\
+  7, TUSB_DESC_ENDPOINT, _ep_notif, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_ep_notif_size), 50,\
+  /* CDC Data Interface (default inactive) */\
+  9, TUSB_DESC_INTERFACE, (uint8_t)((_itfnum)+1), 0, 0, TUSB_CLASS_CDC_DATA, 0, NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK, 0,\
+  /* CDC Data Interface (alternative active) */\
+  9, TUSB_DESC_INTERFACE, (uint8_t)((_itfnum)+1), 1, 2, TUSB_CLASS_CDC_DATA, 0, NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK, 0,\
+  /* Endpoint In */\
+  7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0,\
+  /* Endpoint Out */\
+  7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/device/usbd_pvt.h b/src/device/usbd_pvt.h
index 6a4b30956..7607b9895 100644
--- a/src/device/usbd_pvt.h
+++ b/src/device/usbd_pvt.h
@@ -81,7 +81,7 @@ bool usbd_edpt_claim(uint8_t rhport, uint8_t ep_addr);
 // Release an endpoint without submitting a transfer
 bool usbd_edpt_release(uint8_t rhport, uint8_t ep_addr);
 
-// Check if endpoint transferring is complete
+// Check if endpoint is busy transferring
 bool usbd_edpt_busy(uint8_t rhport, uint8_t ep_addr);
 
 // Stall endpoint
@@ -93,6 +93,7 @@ void usbd_edpt_clear_stall(uint8_t rhport, uint8_t ep_addr);
 // Check if endpoint is stalled
 bool usbd_edpt_stalled(uint8_t rhport, uint8_t ep_addr);
 
+// Check if endpoint is ready (not busy and not stalled)
 TU_ATTR_ALWAYS_INLINE static inline
 bool usbd_edpt_ready(uint8_t rhport, uint8_t ep_addr)
 {