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PEP_ACPI_EVALUATE_CONTROL_METHOD structure (pepfx.h)

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The PEP_ACPI_EVALUATE_CONTROL_METHOD structure specifies an ACPI control method to evaluate, an input argument to supply to this method, and an output buffer for the result of the evaluation.

Syntax

typedef struct _PEP_ACPI_EVALUATE_CONTROL_METHOD {
  PEPHANDLE             DeviceHandle;
  ULONG                 RequestFlags;
  union {
    ULONG       MethodName;
    ANSI_STRING MethodNameString;
  };
  NTSTATUS              MethodStatus;
  PVOID                 CompletionContext;
  ULONG                 InputArgumentCount;
  SIZE_T                InputArgumentSize;
  PACPI_METHOD_ARGUMENT InputArguments;
  ULONG                 OutputArgumentCount;
  SIZE_T                OutputArgumentSize;
  PACPI_METHOD_ARGUMENT OutputArguments;
} PEP_ACPI_EVALUATE_CONTROL_METHOD, *PPEP_ACPI_EVALUATE_CONTROL_METHOD;

Members

DeviceHandle

A PEPHANDLE value that identifies the device's registration for ACPI services. The platform extension plug-in (PEP) supplied this handle in response to a previous PEP_NOTIFY_ACPI_REGISTER_DEVICE notification.

RequestFlags

A set of flags. This member contains one of the following values.

Flag name Value Meaning
PEP_ACPI_ECM_FLAG_NONE 0x0 Not a valid control method name.
PEP_ACPI_ECM_FLAG_RELATIVE_NAME 0x1 The MethodNameUlong member contains a path-relative control method name.
PEP_ACPI_ECM_FLAG_FULLY_QUALIFIED_NAME 0x2 The MethodNameString member contains a fully qualified control method name.

MethodName

A ULONG value that contains the four-character, path-relative name of the ACPI control method.

MethodNameString

An ANSI_STRING structure that contains the fully qualified name of the ACPI control method. This name specifies the path and name of the method in the ACPI namespace. For more information, see Enumerating Child Devices and Control Methods.

MethodStatus

An NTSTATUS value that indicates the status of the evaluation of the ACPI control method. Set this member to STATUS_SUCCESS to indicate that the platform extension plug-in (PEP) successfully completed its evaluation of the method. Set to STATUS_NOT_SUPPORTED to indicate that the PEP does not recognize the control method. Set to STATUS_BUFFER_TOO_SMALL to indicate that the output buffer size specified by the InputArgumentSize member is not large enough to contain the method results.

If the PEP is to evaluate the method asynchronously, set this member to STATUS_PENDING and return from the AcceptAcpiNotification callback. Later, when the evaluation is completed, the PEP calls the CompleteWork routine to notify the Windows power management framework (PoFx) that the evaluation of the control method is complete.

CompletionContext

A pointer to a completion context value. The PEP uses this member only if the control method is evaluated asynchronously. In this case, the PEP supplies this completion context pointer in the call to the CompleteWork routine that notifies the Windows power management framework (PoFx) that the evaluation of the control method is complete. Included in the input parameters to this call is a pointer to a PEP_WORK_ACPI_EVALUATE_CONTROL_METHOD_COMPLETE structure to which the PEP has written the completion context pointer. The context is opaque to the PEP and contains data used internally by PoFx.

InputArgumentCount

The number of input arguments in the input buffer pointed to by the InputArguments member. Each argument starts with an ACPI_METHOD_ARGUMENT structure that specifies the size of the argument. Currently, the maximum InputArgumentCount value is one.

InputArgumentSize

The size, in bytes, of the input buffer pointed to by the InputArguments member.

InputArguments

A pointer to an input buffer that contains an ACPI_METHOD_ARGUMENT structure that specifies the input argument for the specified ACPI control method.

OutputArgumentCount

The number of output arguments in the output buffer pointed to by the OutputArguments member. Each argument starts with an ACPI_METHOD_ARGUMENT structure that specifies the size of the argument. Currently, the maximum allowed OutputArgumentCount value is one.

OutputArgumentSize

On input, the size, in bytes, of the output buffer pointed to by the OutputArguments member. If this buffer is not large enough to contain the result of evaluating the method, the PEP overwrites the OutputArgumentSize input value with the required size, and sets the MethodStatus member to STATUS_BUFFER_TOO_SMALL.

OutputArguments

A pointer to an output buffer to which the PEP writes an ACPI_METHOD_ARGUMENT structure that contains the result of evaluating the specified ACPI control method.

Remarks

This structure is used by the PEP_NOTIFY_ACPI_EVALUATE_CONTROL_METHOD notification. The MethodStatus member contains an output value that the PEP writes to the structure in response to this notification. The OutputArgumentSize member contains an input value supplied by PoFx when the notification is sent. The PEP may overwrite this input value with an output value if the input value is less than the required output buffer size. All other members of this structure contain input values that are supplied by PoFx when the notification is sent.

The unnamed union in this structure contains either the four-character path-relative control method name (if RequestFlags = PEP_ACPI_ECM_FLAG_RELATIVE_NAME) or the fully qualified control method name (if RequestFlags = PEP_ACPI_ECM_FLAG_FULLY_QUALIFIED_NAME).

Requirements

Requirement Value
Minimum supported client Supported starting with Windows 10.
Header pepfx.h (include Pep_x.h)

See also