DXGKDDI_NOTIFY_SURPRISE_REMOVAL callback function (dispmprt.h)
DXGKDDI_NOTIFY_SURPRISE_REMOVAL is called by the operating system when a user disconnects an external display device without notifying the system.
Syntax
DXGKDDI_NOTIFY_SURPRISE_REMOVAL DxgkddiNotifySurpriseRemoval;
NTSTATUS DxgkddiNotifySurpriseRemoval(
[in] PVOID MiniportDeviceContext,
[in] DXGK_SURPRISE_REMOVAL_TYPE RemovalType
)
{...}
Parameters
[in] MiniportDeviceContext
A handle to a context block associated with a display adapter. The display miniport driver's DxgkDdiAddDevice function previously provided this handle to the DirectX graphics kernel subsystem.
[in] RemovalType
A value of type DXGK_SURPRISE_REMOVAL_TYPE that identifies the type of surprise removal event.
Return value
Returns STATUS_SUCCESS if software resources were cleaned up for RemovalType = DxgkRemovalHibernation. If the driver instead returns an error code, the operating system will attempt to reboot the system, as described in the following Remarks section.
Remarks
This callback can be optionally be implemented by Windows Display Driver Model (WDDM) 1.2 and later display miniport drivers.
Note
The operating system calls DxgkDdiNotifySurpriseRemoval only if the display miniport driver indicates support by setting the SupportSurpriseRemovalInHibernation member of the DXGK_DRIVERCAPS structure to 1.
When the OS detects a surprise removal, it notifies the driver as quickly as possible. DxgkDdiNotifySurpriseRemoval is a level zero DDI function, which means that it can be called when a driver has pending GPU workload and/or is running inside other DDI functions. Since a call to this function indicates the graphics hardware has been physically removed or has disappeared from system, any further attempt to access hardware might cause problems such as a hard hang.
The OS categorizes surprise removal as follows:
The surprise removal occurs when the system and graphics device are in a low-power state, such as sleep or hibernation. When the OS resumes from the low power state, it detects this surprise removal and immediately calls the driver's DxgkDdiNotifySurpriseRemoval callback with RemovalType = DxgkRemovalHibernation. There will not likely any pending GPU work or DDI calls in this case, so it should be relatively safe and easy for the driver to handle. Return status details are as follows:
- The OS expects the driver to handle the DxgkDdiNotifySurpriseRemoval call correctly and return STATUS_SUCCESS.
- If the removed graphics device is the power-on self-test (POST) device, the OS will try to reboot the system gracefully regardless of the returned status.
- For a non-POST device, if the driver fails the call and only supports SupportSurpriseRemovalInHibernation in its DXGK_DRIVERCAPS, the OS will reboot the system gracefully. If it supports SupportSurpriseRemoval in DXGK_DRIVERCAPS, the OS will ignore the return status and continue stopping the graphics device. See additional return notes below.
The graphics device is surprise removed/unplugged when it is still running. When the OS detects this type of surprise removal, it immediately calls the driver's DxgkDdiNotifySurpriseRemoval callback with RemovalType = DxgkRemovalPnPNotify. There might still be some pending GPU work or DDI calls to complete in this case. When the driver receives this notification and can handle this surprise removal, the driver should immediately mark this device as surprise removal in its own device context to avoid any hardware access and then return STATUS_SUCCESS back to the OS. The OS will continue calling other DDI functions to clean up the resources and stop the graphics device. As noted below, the driver should only release or clean up the software resources and must not touch or access any hardware in these DDI calls. If the driver cannot handle this surprise removal, it should return a proper failure to the OS. For any failure, the OS will bugcheck the system immediately to avoid any further hardware or data damage.
If the display miniport driver returns STATUS_SUCCESS, the DirectX graphics kernel subsystem will continue to remove the external display adapter from the graphics stack and will call other driver-implemented DxgkDdiXxx kernel-mode functions to release all resources. In this case, the driver must complete its cleanup of software resources in response to calls from the operating system but must not touch or clean any hardware settings. If no other hardware is using the driver, the operating system will unload the driver.
If the driver returns an error code, does not set DXGK_DRIVERCAPS.SupportSurpriseRemovalInHibernation, or does not implement this function, the DirectX graphics kernel subsystem will not call any more driver-implemented DxgkDdiXxx functions and will attempt to reboot the system. In this case, the resource that was allocated before the external display device was disconnected will not be released.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 8 |
| Minimum supported server | Windows Server 2012 |
| Target Platform | Desktop |
| Header | dispmprt.h |
| IRQL | PASSIVE_LEVEL |