EVT_MBB_DEVICE_SEND_DEVICE_SERVICE_SESSION_DATA callback function (mbbcx.h)

Artikel
02/22/2024

A client driver's EvtMbbDeviceSendServiceSessionData event callback function sends device service session data down to its modem device.

Syntax

EVT_MBB_DEVICE_SEND_DEVICE_SERVICE_SESSION_DATA EvtMbbDeviceSendDeviceServiceSessionData;

void EvtMbbDeviceSendDeviceServiceSessionData(
  WDFDEVICE Device,
  DSS_SESSION_ID SessionId,
  WDFMEMORY Data
)
{...}

Parameters

Device

A handle to a framework device object the client driver obtained from a previous call to WdfDeviceCreate.

SessionId

The ID of the device service session obtained from a previous call to MbbAdapterGetSessionId.

Data

A WDFMEMORY object containing the data to pass to the device.

Return value

None

Remarks

MBBCx invokes a client driver's EvtMbbDeviceSendServiceSessionData callback function when an application sends DSS data down to the modem device. After sending the data to the device asynchronously, the client driver must call MbbDeviceSendServiceSessionDataComplete so MBBCx can free the memory allocated for the data.

Example

The following example shows how a client might send DSS data down to its modem device. Error handling has been left out of this example for brevity and clarity.

VOID
MyEvtMbbDeviceSendServiceSessionData(
    _In_ WDFDEVICE Device,
    _In_ DSS_SESSION_ID SessionId,
    _In_ WDFMEMORY Data
)
{
    // Get the device context and NETADAPTER context
    PMY_DEVICE_CONTEXT deviceContext = GetMyDeviceContext(Device);

    // Set up a driver-defined DSS packet structure
    PMY_DSS_PACKET packet = NULL;

    // Get the data to send from the WDFMEMORY object
    size_t bufferSize = 0;
    PVOID buffer = WdfMemoryGetBuffer(Data, 
                                      &bufferSize);

    // Populate the DSS packet
    packet = MyAllocateDssPacket(Data,
                                buffer,
                                bufferSize,
                                SessionId);

    // Send the data asynchronously, which returns STATUS_PENDING when successful
    status = MyModemBusWriteData(deviceContext->BusHandle,
                                 packet);

    // Increment count of sent packets
    deviceContext->DSSPacketsSentCount++;

    // Clean up the memory
    MbbDeviceSendServiceSessionDataComplete(Data,
                                            status);
    MyCleanupDssPacket(packet);
}

Requirements

Requirement	Value
Minimum supported client	Windows 10, version 1809
Target Platform	Universal
Minimum KMDF version	1.27
Header	mbbcx.h
IRQL	PASSIVE_LEVEL

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