// Control.cpp -- IOCTL handlers for usbint driver
// Copyright (C) 1999 by Walter Oney
// All rights reserved
#include "stddcls.h"
#include "driver.h"
#include "ioctls.h"
///////////////////////////////////////////////////////////////////////////////
#pragma PAGEDCODE
NTSTATUS DispatchControl(PDEVICE_OBJECT fdo, PIRP Irp)
{ // DispatchControl
PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
NTSTATUS status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
if (!NT_SUCCESS(status))
return CompleteRequest(Irp, status, 0);
ULONG info = 0;
PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
ULONG cbin = stack->Parameters.DeviceIoControl.InputBufferLength;
ULONG cbout = stack->Parameters.DeviceIoControl.OutputBufferLength;
ULONG code = stack->Parameters.DeviceIoControl.IoControlCode;
switch (code)
{ // process request
case IOCTL_WAITINT : // code == 0x800
{ // IOCTL_WAITINT
// Use up a pending interrupt first. We increment numints each time we
// get an interrupt, and we decrement it each time we complete an IOCTL.
if (InterlockedDecrement(&pdx->numints) >= 0)
{ // pending interrupt
status = STATUS_SUCCESS;
break;
} // pending interrupt
// Pend this IOCTL until an interrupt occurs
InterlockedIncrement(&pdx->numints); // restore counter
status = GenericCacheControlRequest(pdx->pgx, Irp, &pdx->InterruptIrp);
break;
} // IOCTL_WAITINT
default:
status = STATUS_INVALID_DEVICE_REQUEST;
break;
} // process request
IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
return status == STATUS_PENDING ? status : CompleteRequest(Irp, status, info);
} // DispatchControl
