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WdfDmaTransactionWdmGetTransferContext method

[Applies to KMDF only]

The WdfDmaTransactionWdmGetTransferContext method retrieves the WDM transfer context that is associated with a DMA transaction.

Syntax


PVOID WdfDmaTransactionWdmGetTransferContext(
  [in]  WDFDMATRANSACTION DmaTransaction
);

Parameters

DmaTransaction [in]

A handle to an initialized DMA transaction object from which to retrieve the transfer context.

Return value

A pointer to the DMA transfer context (PTRANSFER_CONTEXT) associated with the transaction.

Remarks

The DMA transfer context for a transaction is allocated when the driver creates the transaction.

WdfDmaTransactionWdmGetTransferContext must be used with a DMA enabler that uses DMA version 3. To select version 3, set the WdmDmaVersionOverride member of WDF_DMA_ENABLER_CONFIG to 3.

Your driver can use the DMA transfer context to call the following WDM DMA library routines directly:

You must initialize the DMA transaction before calling WdfDmaTransactionWdmGetTransferContext.

Requirements

Minimum support

Windows 8

Minimum KMDF version

1.11

Header

Wdfdmatransaction.h (include Wdf.h)

Library

Wdf01000.sys (see Framework Library Versioning.)

IRQL

<=DISPATCH_LEVEL

DDI compliance rules

DriverCreate

See also

WdfDmaTransactionCreate

 

 

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