Usb failed packets

/* USB Standard Device Descriptor */
typedef __packed struct _USB_DEVICE_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint16_t  bcdUSB;
  uint8_t  bDeviceClass;
  uint8_t  bDeviceSubClass;
  uint8_t  bDeviceProtocol;
  uint8_t  bMaxPacketSize0;
  uint16_t  idVendor;
  uint16_t  idProduct;
  uint16_t  bcdDevice;
  uint8_t  iManufacturer;
  uint8_t  iProduct;
  uint8_t  iSerialNumber;
  uint8_t  bNumConfigurations;
} USB_DEVICE_DESCRIPTOR;

/* USB 2.0 Device Qualifier Descriptor */
typedef __packed struct _USB_DEVICE_QUALIFIER_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint16_t  bcdUSB;
  uint8_t  bDeviceClass;
  uint8_t  bDeviceSubClass;
  uint8_t  bDeviceProtocol;
  uint8_t  bMaxPacketSize0;
  uint8_t  bNumConfigurations;
  uint8_t  bReserved;
} USB_DEVICE_QUALIFIER_DESCRIPTOR;

/* USB Standard Configuration Descriptor */
typedef __packed struct _USB_CONFIGURATION_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint16_t  wTotalLength;
  uint8_t  bNumInterfaces;
  uint8_t  bConfigurationValue;
  uint8_t  iConfiguration;
  uint8_t  bmAttributes;
  uint8_t  bMaxPower;
} USB_CONFIGURATION_DESCRIPTOR;

/* USB Standard Interface Descriptor */
typedef __packed struct _USB_INTERFACE_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint8_t  bInterfaceNumber;
  uint8_t  bAlternateSetting;
  uint8_t  bNumEndpoints;
  uint8_t  bInterfaceClass;
  uint8_t  bInterfaceSubClass;
  uint8_t  bInterfaceProtocol;
  uint8_t  iInterface;
} USB_INTERFACE_DESCRIPTOR;

/* USB Standard Endpoint Descriptor */
typedef __packed struct _USB_ENDPOINT_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint8_t  bEndpointAddress;
  uint8_t  bmAttributes;
  uint16_t  wMaxPacketSize;
  uint8_t  bInterval;
} USB_ENDPOINT_DESCRIPTOR;

/* USB String Descriptor */
typedef __packed struct _USB_STRING_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
  uint16_t  bString/*[]*/;
} USB_STRING_DESCRIPTOR;

/* USB Common Descriptor */
typedef __packed struct _USB_COMMON_DESCRIPTOR {
  uint8_t  bLength;
  uint8_t  bDescriptorType;
} USB_COMMON_DESCRIPTOR;


#endif  /* __USB_H__ */

/*----------------------------------------------------------------------------
 *      U S B  -  K e r n e l
 *----------------------------------------------------------------------------
 *      Name:    ADCUSER.C
 *      Purpose: Audio Device Class Custom User Module
 *      Version: V1.10
 *----------------------------------------------------------------------------
 *      This software is supplied "AS IS" without any warranties, express,
 *      implied or statutory, including but not limited to the implied
 *      warranties of fitness for purpose, satisfactory quality and
 *      noninfringement. Keil extends you a royalty-free right to reproduce
 *      and distribute executable files created using this software for use
 *      on NXP Semiconductors LPC family microcontroller devices only. Nothing
 *      else gives you the right to use this software.
 *
 * Copyright (c) 2009 Keil - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include "type.h"

#include "usb.h"
#include "audio.h"
#include "usbcfg.h"
#include "usbcore.h"
#include "adcuser.h"

#include "usbaudio.h"

      uint16_t VolCur = 0x0100;     /* Volume Current Value */
const uint16_t VolMin = 0x0000;     /* Volume Minimum Value */
const uint16_t VolMax = 0x0100;     /* Volume Maximum Value */
const uint16_t VolRes = 0x0004;     /* Volume Resolution */

/*
 *  Audio Device Class Interface Get Request Callback
 *   Called automatically on ADC Interface Get Request
 *    Parameters:      None (global SetupPacket and EP0Buf)
 *    Return Value:    TRUE - Success, FALSE - Error
 */

uint32_t ADC_IF_GetRequest (void) {

/*
  Interface = SetupPacket.wIndex.WB.L;
  EntityID  = SetupPacket.wIndex.WB.H;
  Request   = SetupPacket.bRequest;
  Value     = SetupPacket.wValue.W;
  ...
*/

  if (SetupPacket.wIndex.W == 0x0200) {
    /* Feature Unit: Interface = 0, ID = 2 */
    if (SetupPacket.wValue.WB.L == 0) {
      /* Master Channel */
      switch (SetupPacket.wValue.WB.H) {
        case AUDIO_MUTE_CONTROL:
          switch (SetupPacket.bRequest) {
            case AUDIO_REQUEST_GET_CUR:
              EP0Buf[0] = Mute;
              return (TRUE);
          }
          break;
        case AUDIO_VOLUME_CONTROL:
          switch (SetupPacket.bRequest) {
            case AUDIO_REQUEST_GET_CUR:
              *((__packed uint16_t *)EP0Buf) = VolCur;
              return (TRUE);
            case AUDIO_REQUEST_GET_MIN:
              *((__packed uint16_t *)EP0Buf) = VolMin;
              return (TRUE);
            case AUDIO_REQUEST_GET_MAX:
              *((__packed uint16_t *)EP0Buf) = VolMax;
              return (TRUE);
            case AUDIO_REQUEST_GET_RES:
              *((__packed uint16_t *)EP0Buf) = VolRes;
              return (TRUE);
          }
          break;
      }
    }
  }
  return (FALSE);  /* Not Supported */
}


/*
 *  Audio Device Class Interface Set Request Callback
 *   Called automatically on ADC Interface Set Request
 *    Parameters:      None (global SetupPacket and EP0Buf)
 *    Return Value:    TRUE - Success, FALSE - Error
 */

uint32_t ADC_IF_SetRequest (void) {

/*
  Interface = SetupPacket.wIndex.WB.L;
  EntityID  = SetupPacket.wIndex.WB.H;
  Request   = SetupPacket.bRequest;
  Value     = SetupPacket.wValue.W;
  ...
*/

  if (SetupPacket.wIndex.W == 0x0200) {
    /* Feature Unit: Interface = 0, ID = 2 */
    if (SetupPacket.wValue.WB.L == 0) {
      /* Master Channel */
      switch (SetupPacket.wValue.WB.H) {
        case AUDIO_MUTE_CONTROL:
          switch (SetupPacket.bRequest) {
            case AUDIO_REQUEST_SET_CUR:
              Mute = EP0Buf[0];
              return (TRUE);
          }
          break;
        case AUDIO_VOLUME_CONTROL:
          switch (SetupPacket.bRequest) {
            case AUDIO_REQUEST_SET_CUR:
              VolCur = *((__packed uint16_t *)EP0Buf);
              return (TRUE);
          }
          break;
      }
    }
  }
  return (FALSE);  /* Not Supported */
}


/*
 *  Audio Device Class EndPoint Get Request Callback
 *   Called automatically on ADC EndPoint Get Request
 *    Parameters:      None (global SetupPacket and EP0Buf)
 *    Return Value:    TRUE - Success, FALSE - Error
 */

uint32_t ADC_EP_GetRequest (void) {

/*
  EndPoint = SetupPacket.wIndex.WB.L;
  Request  = SetupPacket.bRequest;
  Value    = SetupPacket.wValue.W;
  ...
*/
  return (FALSE);  /* Not Supported */
}


/*
 *  Audio Device Class EndPoint Set Request Callback
 *   Called automatically on ADC EndPoint Set Request
 *    Parameters:      None (global SetupPacket and EP0Buf)
 *    Return Value:    TRUE - Success, FALSE - Error
 */

uint32_t ADC_EP_SetRequest (void) {

/*
  EndPoint = SetupPacket.wIndex.WB.L;
  Request  = SetupPacket.bRequest;
  Value    = SetupPacket.wValue.W;
  ...
*/
  return (FALSE);  /* Not Supported */
}

After searching the internet, the best I have come with is that, it could have something to do
with usb.h and adcuser.c

in windows 7 every 50 to 80 us SYNC_RESET_PIPE_AND_CLEAR_STALL is being issued and failing causing lost packets and out of sequence audio packets

case URB_FUNCTION_SYNC_CLEAR_STALL and case case URB_FUNCTION_SYNC_RESET_PIPE. These allow client drivers to clear the ENDPOINT_HALT feature on the device, or reset the pipe on the host side, respectively, without affecting the data toggle on the host side. If the device does not reset the data toggle when it should, then the client driver can compensate for this defect by not resetting the host-side data toggle.

If the data toggle is reset on the host side but not on the device side, packets will get out of sequence, and the device might drop packets

???????