DMA_SUSPEND_HANDLER callback function (netdma.h)

Article
10/21/2021

Note The NetDMA interface is not supported

in Windows 8 and later.

The ProviderSuspendDma function suspends the DMA transfers that are currently in progress on a DMA channel.

Syntax

DMA_SUSPEND_HANDLER DmaSuspendHandler;

NTSTATUS DmaSuspendHandler(
  [in]  PVOID ProviderChannelContext,
  [out] PPHYSICAL_ADDRESS *pLastDescriptor
)
{...}

Parameters

[in] ProviderChannelContext

A pointer that identifies a DMA channel's context area. The DMA provider returned this handle to NetDMA at the location that is specified in the pProviderChannelContext parameter of the ProviderAllocateDmaChannel function.

[out] pLastDescriptor

A pointer to a variable that contains the physical address of the last successfully processed DMA descriptor. The DMA provider provides this address before returning from ProviderSuspendDma.

Return value

ProviderSuspendDma returns one of the following status values:

Return code	Description
STATUS_SUCCESS	The operation completed successfully.
STATUS_UNSUCCESSFUL	The operation failed for unspecified reasons.

Remarks

The ProviderSuspendDma function is an optional function for NetDMA providers. The NetDMA interface can call the ProviderSuspendDma function, if any, to temporarily suspend any DMA transfers that are in progress on a DMA channel.

The DMA provider completes the transfer of the current DMA descriptor before it returns from ProviderSuspendDma. If completion status reporting is enabled, the DMA engine writes the NetDmaTransferStatusSuspend status in the address that is specified in the CompletionVirtualAddress and CompletionPhysicalAddress members in the NET_DMA_CHANNEL_PARAMETERS structure.

While the DMA transfers are suspended, the NetDMA interface can modify the DMA descriptor linked list (for example, to insert or delete descriptors).

The NetDMA interface calls the ProviderResumeDma function to resume DMA operations that were suspended by calling ProviderSuspendDma.

NetDMA calls ProviderSuspendDma at IRQL <= DISPATCH_LEVEL.

Requirements

Requirement	Value
Minimum supported client	Supported for NetDMA 1.0 drivers in Windows Vista.
Target Platform	Windows
Header	netdma.h (include Netdma.h)
IRQL	<= DISPATCH_LEVEL