WdfDmaTransactionRelease function (wdfdmatransaction.h)
[Applies to KMDF only]
The WdfDmaTransactionRelease method terminates a specified DMA transaction without deleting the associated DMA transaction object.
Syntax
NTSTATUS WdfDmaTransactionRelease(
[in] WDFDMATRANSACTION DmaTransaction
);
Parameters
[in] DmaTransaction
A handle to a DMA transaction object that the driver obtained from a previous call to WdfDmaTransactionCreate.
Return value
WdfDmaTransactionRelease returns STATUS_SUCCESS if the operation succeeds. Otherwise, the method might return the following value:
| Return code | Description |
|---|---|
|
The driver has already released or deleted the transaction object that the DmaTransaction parameter specified. |
This method also might return other NTSTATUS values.
A bug check occurs if the driver supplies an invalid object handle.
Remarks
The WdfDmaTransactionRelease method flushes transfer buffers and releases all of the system resources that are associated with the DMA transaction. The transaction object is not deleted and can be reused. For more information about reusing transaction objects, see Reusing DMA Transaction Objects.
If WdfDmaTransactionInitializeXxx returns success but WdfDmaTransactionExecute returns an error value, your driver must call WdfDmaTransactionRelease.
Examples
The following code example terminates the DMA transaction that the specified DMA transaction object represents, but it does not delete the DMA transaction object.
NTSTATUS status;
status = WdfDmaTransactionRelease(dmaTransaction);
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Minimum KMDF version | 1.0 |
| Header | wdfdmatransaction.h (include Wdf.h) |
| Library | Wdf01000.sys (see Framework Library Versioning.) |
| IRQL | <=DISPATCH_LEVEL |
| DDI compliance rules | DriverCreate(kmdf), KmdfIrql(kmdf), KmdfIrql2(kmdf), KmdfIrqlExplicit(kmdf) |