UfxDeviceNotifyDetach function (ufxclient.h)

Notifies UFX that the device's USB cable has been detached.

Syntax

VOID UfxDeviceNotifyDetach(
 [in] UFXDEVICE UfxDevice
);

Parameters

[in] UfxDevice

A handle to a UFX device object that the driver created by calling UfxDeviceCreate.

Return value

None

Remarks

This method is called by the client driver when it receives a USB cable detach event. Once the detach event is processed, all endpoints should be disabled and device should move to a low power mode.

The client driver typically calls UfxDeviceNotifyDetach from its EVT_WDF_INTERRUPT_DPC callback function, as shown in the following example.

VOID 
DeviceInterrupt_EvtInterruptDpc (
 _In_ WDFINTERRUPT Interrupt,
 _In_ WDFOBJECT AssociatedObject
 )
/*++

Routine Description:

 'EVT_WDF_INTERRUPT_DPC' handler for the device interrupt object.

Arguments:

 Interrupt - Associated interrupt object.

 AssociatedObject - FDO Object

--*/
{
 WDFDEVICE WdfDevice;
 PDEVICE_INTERRUPT_CONTEXT InterruptContext;
 PCONTROLLER_CONTEXT ControllerContext;
 BOOLEAN Attached;
 BOOLEAN GotAttachOrDetach;
 CONTROLLER_EVENT ControllerEvent;

 UNREFERENCED_PARAMETER(Interrupt);

 TraceEntry();

 WdfDevice = (WDFDEVICE) AssociatedObject;
 ControllerContext = DeviceGetControllerContext(WdfDevice);

 WdfSpinLockAcquire(ControllerContext->DpcLock);

 WdfInterruptAcquireLock(ControllerContext->DeviceInterrupt);
 Attached = ControllerContext->Attached;
 GotAttachOrDetach = ControllerContext->GotAttachOrDetach;
 ControllerContext->GotAttachOrDetach = FALSE;
 WdfInterruptReleaseLock(ControllerContext->DeviceInterrupt);

 //
 // Handle attach/detach events
 //
 if (GotAttachOrDetach) {
 if (Attached && ControllerContext->WasAttached) {
 //
 // We must have gotten at least one detach. Need to reset the state.
 // 
 ControllerContext->RemoteWakeupRequested = FALSE;
 ControllerContext->Suspended = FALSE;
 UfxDeviceNotifyDetach(ControllerContext->UfxDevice);
 }

 if (Attached) {
 ControllerContext->RemoteWakeupRequested = FALSE;
 ControllerContext->Suspended = FALSE;
 UfxDeviceNotifyAttach(ControllerContext->UfxDevice);
 }
 }

 ControllerContext->WasAttached = Attached;

 InterruptContext = DeviceInterruptGetContext(ControllerContext->DeviceInterrupt);

 //
 // #### TODO: Insert code to read and dispatch events from the controller ####
 // 

 // The sample will assume an endpoint event of EndpointEventTransferComplete
 ControllerEvent.Type = EventTypeEndpoint;
 ControllerEvent.u.EndpointEvent = EndpointEventTransferComplete;
 
 //
 // Handle events from the controller
 //
 switch (ControllerEvent.Type) {
 case EventTypeDevice:
 HandleDeviceEvent(WdfDevice, ControllerEvent.u.DeviceEvent);
 break;

 case EventTypeEndpoint:
 HandleEndpointEvent(WdfDevice, ControllerEvent.u.EndpointEvent);
 break;
 }

 WdfSpinLockRelease(ControllerContext->DpcLock);

 TraceExit();
}

Requirements