DMA_CHANNEL_FREE_HANDLER callback function (netdma.h)

Article
02/22/2024

Note The NetDMA interface is not supported

in Windows 8 and later.

The ProviderFreeDmaChannel function frees a DMA channel that the ProviderAllocateDmaChannel function previously allocated.

Syntax

DMA_CHANNEL_FREE_HANDLER DmaChannelFreeHandler;

void DmaChannelFreeHandler(
  [in] PVOID ProviderChannelContext
)
{...}

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.

Return value

None

Remarks

The NetDMA interface calls a DMA provider driver's ProviderFreeDmaChannel function to free a DMA channel. Before the NetDMA interface calls ProviderFreeDmaChannel, it ensures that there are no outstanding DMA operations on this channel.

After the NetDMA interface calls ProviderFreeDmaChannel, it does not call any ProviderXxx functions for the freed channel.

The NetDMA interface frees all of the allocated DMA channels before it returns from the NetDmaProviderStop function.

NetDMA calls ProviderFreeDmaChannel 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