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Issuing NDIS Wake Reason Status Indications

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If a miniport driver supports NDIS wake reason status indications (NDIS_STATUS_PM_WAKE_REASON), it must generate this status indication immediately after the network adapter generates a wake-up event and the adapter resumes to a full-power state.

Note Support for NDIS wake reason status indications is optional for Mobile Broadband (MB) miniport drivers.

The miniport driver is configured with power management (PM) parameters through an object identifier (OID) set request of OID_PM_PARAMETERS. This OID request specifies the PM parameters through an NDIS_PM_PARAMETERS structure.

The NDIS_PM_PARAMETERS structure specifies the parameters for the following types of wake-up events.

Received Packet Wake-up Events
The network adapter generates a wake-up event if it receives a packet that matched a wake-on-LAN (WOL) pattern. WOL patterns include the following:

  • Media-independent WOL patterns, such as magic packets or TCP/IP data patterns within the packet payload. For example, the NDIS_PM_PARAMETERS structure could specify a WOL pattern for a TCP SYN frame.

  • Media-specific WOL patterns, such as an EAPOL request identifier packet or mobile broadband (MB) Short Message Service (SMS) message.

  • Wildcard patterns that match a receive filter specified through an OID set request of OID_GEN_CURRENT_PACKET_FILTER.

Note For this type of wake reason status indication, the network adapter must be able to save the received packet. The driver must return the received packet within the status indication.

WOL patterns are specified through the EnabledWoLPacketPatterns member of the NDIS_PM_PARAMETERS structure.

Media-Specific Wake-up Events
The network adapter generates a wake-up event because of a media-specific reason, such as a disassociation from an 802.11 access point (AP) or the receipt of a mobile broadband (MB) Short Message Service (SMS) message.

Wake-up events of this type are specified through the MediaSpecificWakeUpEvents member of the NDIS_PM_PARAMETERS structure.

Media-Independent Wake-up Events
The network adapter generates a wake-up event because of a media-independent reason, such as media connection or disconnection.

Wake-up events of this type are specified through the WakeUpFlags member of the NDIS_PM_PARAMETERS structure.

If the network adapter generated a wake-up signal, the miniport driver must issue an NDIS_STATUS_PM_WAKE_REASON status indication. The driver does this while it is handling the OID set request of OID_PNP_SET_POWER for the transition of the adapter to a full-power state.

Note The miniport driver must issue an NDIS_STATUS_PM_WAKE_REASON status indication before it issues a status indication that is related to the wake-up event. For example, if the wake-up event was due to a change in the media connectivity state, the miniport driver must issue an NDIS_STATUS_LINK_STATE status indication after it has issued the NDIS_STATUS_PM_WAKE_REASON status indication.

When the miniport driver issues the NDIS_STATUS_PM_WAKE_REASON status indication, it must follow these steps:

  1. The miniport driver must allocate a buffer that is large enough to contain the following:

    • An NDIS_PM_WAKE_REASON structure.

    • An NDIS_PM_WAKE_PACKET structure along with the received packet (wake packet) that caused the network adapter to generate the wake-up event.

      Note The miniport driver does not need to allocate this buffer space if it indicates media-specific or media-independent wake-up events.

  2. The miniport driver initializes an NDIS_PM_WAKE_REASON structure at the start of the buffer. The driver sets the WakeReason member to an NDIS_PM_WAKE_REASON_TYPE enumeration value that defines the type of the wake-up event.

    For example, if the miniport driver is indicating a received packet wake-up event, it must set the WakeReason member to NdisWakeReasonPacket. Otherwise, the driver sets the WakeReason member to the enumeration value that best describes the media-specific or media-independent wake-up event.

  3. If the miniportdriver is issuing an NDIS_STATUS_PM_WAKE_REASON status indication for a received packet wake-up event, it must follow these steps:

    1. The miniport driver sets the InfoBufferOffset member to the offset of an NDIS_PM_WAKE_PACKET structure that follows the NDIS_PM_WAKE_REASON structure in the buffer.

      Note The miniport driver must align the start of the NDIS_PM_WAKE_PACKET structure on a 64-bit boundary.

    2. The miniport driver sets the InfoBufferSize member to the size of the NDIS_PM_WAKE_PACKET structure plus the size of the packet that caused the wake-up event.

    3. The miniport driver initializes an NDIS_PM_WAKE_PACKET structure following the NDIS_PM_WAKE_REASON structure in the buffer.

      The miniport driver sets the members of the NDIS_PM_WAKE_PACKET structure as follows:

      • The PatternId member is set to the identifier of the WOL pattern that matches the wake packet. This identifier is specified by the PatternId member of the NDIS_PM_WOL_PATTERN structure that is passed to the driver during an OID set request of OID_PM_ADD_WOL_PATTERN.

      • The PatternFriendlyName member is set to the user-readable description of the wake pattern that is specified by the PatternId member. This value is specified by the FriendlyName member of the NDIS_PM_WOL_PATTERN structure.

        Note The miniport driver does not need to initialize this member. NDIS sets the PatternFriendlyName member to the correct value before it passes the NDIS_PM_WAKE_PACKET structure to overlying drivers.

      • The OriginalPacketSize member is set to the length of the packet as received by the network adapter.

      • The SavedPacketSize member must be set to the length of the packet that is being reported through the NDIS_STATUS_PM_WAKE_REASON status indication.

        Note The value of this member must not be greater than the value that the miniport driver set in the MaxWoLPacketSaveBuffer member of the NDIS_PM_CAPABILITIES structure. The driver returns this structure when it reports its wake packet indication capabilities. For more information, see Reporting Wake Reason Status Indication Capabilities.

      • The SavedPacketOffset member must be set to the offset, in units of bytes, to the wake packet that follows the NDIS_PM_WAKE_PACKET structure.

        Note The miniport driver must align the start of the wake packet on a 64-bit boundary in the buffer.

    4. The miniport copies the wake packet into the buffer at the offset specified by the SavedPacketOffset member.

  4. If the miniport driver is issuing an NDIS_STATUS_PM_WAKE_REASON status indication for a media-specific or media-independent wake-up event, it sets the InfoBufferOffset and InfoBufferSize members of the NDIS_PM_WAKE_REASON structure to zero.

  5. The miniport driver initializes an NDIS_STATUS_INDICATION structure. The driver sets the StatusCode member to NDIS_STATUS_PM_WAKE_REASON. The driver also sets the StatusBuffer member to point to the buffer, and sets the StatusBufferLength to the length, in bytes, of the buffer.

  6. The miniport driver calls NdisMIndicateStatusEx and passes a pointer to the NDIS_STATUS_INDICATION structure in the StatusIndication parameter.

Note After the miniport driver issues the NDIS_STATUS_PM_WAKE_REASON status indication for a received packet wake-up event, it must indicate this received packet by calling NdisMIndicateReceiveNetBufferLists.