请大侠分析下面代码蓝屏问题，谢谢了，给分

ULONG urbSize = GET_SELECT_INTERFACE_REQUEST_SIZE(pid->bNumEndpoints);
PURB urb = (PURB)ExAllocatePool(NonPagedPool,urbSize);

if (!urb)
{
    status = STATUS_NO_MEMORY;
    KdPrint((" - ErrorSTATUS_NO_MEMORYn\n"));
}

RtlZeroMemory(urb,urbSize);

UsbBuildSelectInterfaceRequest(urb,urbSize,pdx->hconfig,2,(UCHAR)0);
KdPrint(("...Start select interface \n"));
status = SendAwaitUrb(fdo, urb);//此句就蓝屏了
if (!NT_SUCCESS(status))
{
    KdPrint(( " - Error %X trying to select interface\n", status));
    return status;
}
else
{
    KdPrint((" select interface OK\n"));
}

蓝屏到SendAwaitUrb里面去找，另外蓝屏代码是什么

好像你urb没有设置完，参考以下代码（来自Programming the Microsoft Windows Driver Model(2nd) ）

UsbBuildSelectInterfaceRequest(urb, size, pdx->hconfig, 0, 1);
urb->UrbSelectInterface.Interface.Length = GET_USBD_INTERFACE_SIZE(npipes);
urb->UrbSelectInterface.Interface.Pipes[0].MaximumTransferSize =  PAGE_SIZE;
NTSTATUS status = SendAwaitUrb(fdo, &urb);

另外，那个2和0 是不是放反了？