怎样发送irp给获得的串口指针？？（高分求助）

我的问题是这样的：
在我的dispatch pnp 例程中，处理irp_mn_start_device时，需要获得串口指针，然后打开串口，然后配置串口，监听串口。
现在获得串口指针已经成功，但是打开串口时总是会导致page fault或者自动重启。
我猜测是构建的irp不对，或者发送的方式不对， 恳请高手斧正！！

RtlInitUnicodeString( &devx->SerialDeviceName,L\"\\\\Device\\\\Serial0\" );

//Get pointer to serial port        
status = IoGetDeviceObjectPointer(
&devx->SerialDeviceName,
FILE_ALL_ACCESS,
&pFile,
&pSerialDO); //get pSerialDO==the address of PDO

然后帖出我的打开串口的例程，主要问题是irp如何创建，还有如何发送给获得的指针pSerialDO

NTSTATUS AGSCallSerialOpen( IN PDEVICE_OBJECT DeviceObject )
{
NTSTATUS status = STATUS_SUCCESS;
PDEVICE_EXTENSION devx = (PDEVICE_EXTENSION)DeviceObject->DeviceExtension;
PSMARTCARD_EXTENSION SmartcardExtension = &devx->SmartcardExtension;
PREADER_EXTENSION readerx = SmartcardExtension->ReaderExtension;
KEVENT Event;
PIO_STACK_LOCATION irpstack;
PIRP OpenIrp;

OpenIrp = IoAllocateIrp((DeviceObject->StackSize ),FALSE);
//这个地方可能有错
irpstack = IoGetNextIrpStackLocation( OpenIrp );
irpstack->FileObject = pFileObj;//ioGetDeviceObjectPointer中的那个FileObject

irpstack->MajorFunction = IRP_MJ_CREATE;
irpstack->DeviceObject = readerx->SerialDeviceObject;
   irpstack->Parameters.Create.Options = 0;
   irpstack->Parameters.Create.ShareAccess = 0;
   irpstack->Parameters.Create.FileAttributes = 0;
   irpstack->Parameters.Create.EaLength = 0;
//
// initialize an event for process synchronization. The event is passed
// to our completion routine and will be set when the serial driver is done
//
   KeInitializeEvent(
        &Event,
        NotificationEvent,
        FALSE
        );  
  
    // Our IoCompletionRoutine sets only our event
//S:registers an IoCompletion routine to be called when the next-lower-level driver
//has completed the requested operation for the given IRP.
    IoSetCompletionRoutine (
        OpenIrp,
        AGSIoCompletion,
        DeviceObject,
        TRUE,
        TRUE,
        TRUE
        );

    // Call the serial driver
//S:sends an IRP to the next-lower-level driver(SERIAL DRIVER) after
//the caller has set up the I/O stack location in the IRP for that driver
    status = IoCallDriver(readerx->SerialDeviceObject, OpenIrp);
  
// Wait until the serial driver has processed the Irp
    if (status == STATUS_PENDING)
{
        status = KeWaitForSingleObject(
            &Event,
            Executive,
            KernelMode,
            FALSE,
            NULL
            );

        ASSERT (STATUS_SUCCESS == status);
        status = OpenIrp->IoStatus.Status;
    }

    return status;
}

我把获得的串口指针保存在了readerx->SerialDeviceObject。
现在是一头雾水，因为我的status = IoCreateDevice( pDriverObject,
sizeof(DEVICE_EXTENSION),
&(UNICODE_STRING)DevName,
FILE_DEVICE_SMARTCARD,
0, FALSE,
&DeviceObject );
DeviceObject和获得的指针没有IoAttachDeviceToDeviceStack，这种情况下必须自己构建一个irp来发送给串口吧，
但是这种情况下如何处理？
尤其是irp的构建，irpstack的初始化，还有对于用
iogetdeviceobjectpointer获得的deviceobject的使用，着实没有什么头绪。
希望大家提出宝贵的意见，谢谢！！ :)
我会不吝惜分数的