ControllerControl routine

The ControllerControl routine starts a data transfer operation.


DRIVER_CONTROL ControllerControl;

  _In_    struct _DEVICE_OBJECT *DeviceObject,
  _Inout_ struct _IRP           *Irp,
  _In_    PVOID                 MapRegisterBase,
  _In_    PVOID                 Context
{ ... }


DeviceObject [in]

Caller-supplied pointer to a DEVICE_OBJECT structure. This is the device object for the target device, previously created by the driver's AddDevice routine.

Irp [in, out]

Caller-supplied pointer to an IRP structure that describes the I/O operation, if the driver has a StartIo routine. Otherwise, not used.

MapRegisterBase [in]

Not used.

Context [in]

Caller-supplied pointer to driver-defined context information, specified in a previous call to IoAllocateController.

Return value

The routine must return one of the enumerated values defined by IO_ALLOCATION_ACTION.


A driver's ControllerControl routine executes in an arbitrary thread context at IRQL = DISPATCH_LEVEL.

To register a ControllerControl routine for a specific device object, a driver must call IoCreateController to obtain a controller object, then call IoAllocateController to request use of the controller and to supply the ControllerControl routine's address. When the controller is free, the system calls the ControllerControl routine.

For detailed information about implementing a ControllerControl routine, see Writing ControllerControl Routines. Also see Controller Objects.


To define a ControllerControl callback routine, you must first provide a function declaration that identifies the type of callback routine you're defining. Windows provides a set of callback function types for drivers. Declaring a function using the callback function types helps Code Analysis for Drivers, Static Driver Verifier (SDV), and other verification tools find errors, and it's a requirement for writing drivers for the Windows operating system.

For example, to define a ControllerControl callback routine that is named MyControllerControl, use the DRIVER_CONTROL type as shown in this code example:

DRIVER_CONTROL MyControllerControl;

Then, implement your callback routine as follows:

    struct _DEVICE_OBJECT  *DeviceObject,
    struct _IRP  *Irp,
    PVOID  MapRegisterBase,
    PVOID  Context
      // Function body

The DRIVER_CONTROL function type is defined in the Wdm.h header file. To more accurately identify errors when you run the code analysis tools, be sure to add the _Use_decl_annotations_ annotation to your function definition. The _Use_decl_annotations_ annotation ensures that the annotations that are applied to the DRIVER_CONTROL function type in the header file are used. For more information about the requirements for function declarations, see Declaring Functions by Using Function Role Types for WDM Drivers. For information about _Use_decl_annotations_, see Annotating Function Behavior.


Target platform


Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)


Called at DISPATCH_LEVEL (see Remarks section).



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