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GetDMACommand

Method to retrieve a pointer to an IODMACommand from the request.

Declaration

IODMACommand * GetDMACommand ( 
 SCSIParallelTaskIdentifierparallelTask );

Parameters

  • parallelTask:

    A valid SCSIParallelTaskIdentifier.

Return Value

returns pointer to an IODMACommand which is used in conjunction with the task.

Overview

For devices utilizing DMA, the IODMACommand object should be obtained via GetDMACommand(). The subclass is responsible for calling prepare() on the IODMACommand object using the proper offset obtained via GetDataBufferOffset() and correct size obtained via GetRequestedDataTransferCount(). The subclass is further responsible for calling complete() on the IODMACommand object once all DMA operations have finished. NB: Subclasses should not call IODMACommand::setMemoryDescriptor().

See Also

Miscellaneous