Source code of Windows XP (NT5)
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195 lines
4.5 KiB

/*++
Copyright (c) 1996 Microsoft Corporation
Module Name:
power.c
Abstract: NULL filter driver -- boilerplate code
Author:
ervinp
Environment:
Kernel mode
Revision History:
--*/
#include <WDM.H>
#include "filter.h"
NTSTATUS VA_Power(struct DEVICE_EXTENSION *devExt, PIRP irp)
/*++
Routine Description:
Dispatch routine for Power IRPs (MajorFunction == IRP_MJ_Power)
Note: We may or may not have set the DO_POWER_PAGABLE bit
for the filter device object in AddDevice().
Therefore, we don't know whether or not this function
can be called at DISPATCH_LEVEL; so the power-handling
code must be locked.
Arguments:
devExt - device extension for targetted device object
irp - Io Request Packet
Return Value:
NT status code
--*/
{
PIO_STACK_LOCATION irpSp;
NTSTATUS status;
irpSp = IoGetCurrentIrpStackLocation(irp);
DBGOUT(("VA_Power, minorFunc = %d ", (ULONG)irpSp->MinorFunction));
switch (irpSp->MinorFunction){
case IRP_MN_SET_POWER:
switch (irpSp->Parameters.Power.Type) {
case SystemPowerState:
/*
* For system power states, just pass the IRP down.
*/
break;
case DevicePowerState:
switch (irpSp->Parameters.Power.State.DeviceState) {
case PowerDeviceD0:
/*
* Resume from APM Suspend
*
* Do nothing here;
* Send down the read IRPs in the completion
* routine for this (the power) IRP.
*/
break;
case PowerDeviceD1:
case PowerDeviceD2:
case PowerDeviceD3:
/*
* Suspend
*/
if (devExt->state == STATE_STARTED){
devExt->state = STATE_SUSPENDED;
}
break;
}
break;
}
break;
}
/*
* Whether we are completing or relaying this power IRP,
* we must call PoStartNextPowerIrp.
*/
PoStartNextPowerIrp(irp);
/*
* Send the IRP down the driver stack,
* using PoCallDriver (not IoCallDriver, as for non-power irps).
*/
IoCopyCurrentIrpStackLocationToNext(irp);
IncrementPendingActionCount(devExt);
IoSetCompletionRoutine( irp,
VA_PowerComplete,
(PVOID)devExt, // context
TRUE,
TRUE,
TRUE);
status = PoCallDriver(devExt->physicalDevObj, irp);
return status;
}
NTSTATUS VA_PowerComplete(
IN PDEVICE_OBJECT devObj,
IN PIRP irp,
IN PVOID context)
/*++
Routine Description:
Completion routine for Power IRPs (MajorFunction == IRP_MJ_Power)
Arguments:
devObj - targetted device object
irp - Io Request Packet
context - context value passed to IoSetCompletionRoutine by VA_Power
Return Value:
NT status code
--*/
{
PIO_STACK_LOCATION irpSp;
struct DEVICE_EXTENSION *devExt = (struct DEVICE_EXTENSION *)context;
ASSERT(devExt);
ASSERT(devExt->signature == DEVICE_EXTENSION_SIGNATURE);
irpSp = IoGetCurrentIrpStackLocation(irp);
ASSERT(irpSp->MajorFunction == IRP_MJ_POWER);
if (NT_SUCCESS(irp->IoStatus.Status)){
switch (irpSp->MinorFunction){
case IRP_MN_SET_POWER:
switch (irpSp->Parameters.Power.Type){
case DevicePowerState:
switch (irpSp->Parameters.Power.State.DeviceState){
case PowerDeviceD0:
if (devExt->state == STATE_SUSPENDED){
devExt->state = STATE_STARTED;
}
break;
}
break;
}
break;
}
}
/*
* Decrement the pendingActionCount, which we incremented in VA_Power.
*/
DecrementPendingActionCount(devExt);
return STATUS_SUCCESS;
}