windows-nt/Source/XPSP1/NT/drivers/serial/ser71051/flush.c

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2020-09-26 03:20:57 -05:00
/*++
Copyright (c) 1991, 1992, 1993 Microsoft Corporation
Module Name:
flush.c
Abstract:
This module contains the code that is very specific to flush
operations in the serial driver
Author:
Anthony V. Ercolano 26-Sep-1991
Environment:
Kernel mode
Revision History :
--*/
#include "precomp.h"
NTSTATUS
SerialStartFlush(
IN PSERIAL_DEVICE_EXTENSION Extension
);
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGESRP0,SerialFlush)
#pragma alloc_text(PAGESRP0,SerialStartFlush)
#endif
NTSTATUS
SerialFlush(
IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp
)
/*++
Routine Description:
This is the dispatch routine for flush. Flushing works by placing
this request in the write queue. When this request reaches the
front of the write queue we simply complete it since this implies
that all previous writes have completed.
Arguments:
DeviceObject - Pointer to the device object for this device
Irp - Pointer to the IRP for the current request
Return Value:
Could return status success, cancelled, or pending.
--*/
{
PSERIAL_DEVICE_EXTENSION Extension = DeviceObject->DeviceExtension;
NTSTATUS status;
PAGED_CODE();
SerialDump(
SERIRPPATH,
("SERIAL: Dispatch entry for: %x\n",Irp)
);
SerialDump(SERTRACECALLS, ("SERIAL: Entering SerialFlush\n"));
Irp->IoStatus.Information = 0L;
if ((status = SerialIRPPrologue(Irp, Extension)) == STATUS_SUCCESS) {
if (SerialCompleteIfError(DeviceObject, Irp) != STATUS_SUCCESS) {
SerialDump(SERTRACECALLS, ("SERIAL: Leaving SerialFlush (1)\n"));
return STATUS_CANCELLED;
}
SerialDump(SERTRACECALLS, ("SERIAL: Leaving SerialFlush (2)\n"));
return SerialStartOrQueue(Extension, Irp, &Extension->WriteQueue,
&Extension->CurrentWriteIrp, SerialStartFlush);
} else {
Irp->IoStatus.Status = status;
if (!NT_SUCCESS(status)) {
SerialCompleteRequest(Extension, Irp, IO_NO_INCREMENT);
}
SerialDump(SERTRACECALLS, ("SERIAL: Leaving SerialFlush (3)\n"));
return status;
}
}
NTSTATUS
SerialStartFlush(
IN PSERIAL_DEVICE_EXTENSION Extension
)
/*++
Routine Description:
This routine is called if there were no writes in the queue.
The flush became the current write because there was nothing
in the queue. Note however that does not mean there is
nothing in the queue now! So, we will start off the write
that might follow us.
Arguments:
Extension - Points to the serial device extension
Return Value:
This will always return STATUS_SUCCESS.
--*/
{
PIRP NewIrp;
PAGED_CODE();
Extension->CurrentWriteIrp->IoStatus.Status = STATUS_SUCCESS;
//
// The following call will actually complete the flush.
//
SerialGetNextWrite(
&Extension->CurrentWriteIrp,
&Extension->WriteQueue,
&NewIrp,
TRUE,
Extension
);
if (NewIrp) {
ASSERT(NewIrp == Extension->CurrentWriteIrp);
SerialStartWrite(Extension);
}
return STATUS_SUCCESS;
}