IPnpCallbackHardware::OnReleaseHardware method

[Applies to UMDF 1.x only]

The OnReleaseHardware method notifies a driver to perform operations that are necessary when the specified hardware is no longer accessible.

Syntax


HRESULT OnReleaseHardware(
  [in]  IWDFDevice *pWdfDevice
);

Parameters

pWdfDevice [in]

A pointer to the IWDFDevice interface for the device object of the device that is no longer accessible.

Return value

OnReleaseHardware returns S_OK if the operation succeeds. Otherwise, this method returns one of the error codes that are defined in Winerror.h. Do not return HRESULT_FROM_NT(STATUS_NOT_SUPPORTED).

This method must use the HRESULT_FROM_NT macro to return a specific HRESULT value to return status to a kernel-mode client. For more information, see Supporting Kernel-mode Clients.

Remarks

A driver registers the IPnpCallbackHardware interface when the driver calls the IWDFDriver::CreateDevice method to create a device object.

The OnReleaseHardware method must free resources that were allocated during the call to the driver's IPnpCallbackHardware::OnPrepareHardware method whether OnPrepareHardware succeeded or failed. Therefore, OnReleaseHardware must be able to handle the cleanup of partial resources.

For more information, see Finding and Mapping Hardware Resources in a UMDF Driver.

Requirements

Header

Wudfddi.h (include Wudfddi.h)

See also

IPnpCallbackHardware
IPnpCallbackHardware::OnPrepareHardware
IPnpCallbackHardware2::OnReleaseHardware
IWDFDevice
IWDFDriver::CreateDevice

 

 

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