Bewerken

Delen via

Querying timestamping capabilities and configuration

  • Artikel

Once the miniport driver is initialized, overlying drivers and applications can issue the following OID query requests to obtain hardware and software timestamping information.

  • OID_TIMESTAMP_CAPABILITY. An overlying driver issues an object identifier (OID) query request of OID_TIMESTAMP_CAPABILITY to obtain the hardware timestamping capabilities of the NIC and software timestamping capabilities of the miniport driver.

  • OID_TIMESTAMP_CURRENT_CONFIG. An overlying driver issues an OID query request of OID_TIMESTAMP_CURRENT_CONFIG to obtain the current timestamping configuration of the NIC.

  • OID_TIMESTAMP_GET_CROSSTIMESTAMP. An overlying driver issues an OID query request of OID_TIMESTAMP_GET_CROSSTIMESTAMP to obtain the cross timestamp from the NIC hardware. Precision Time Protocol (PTP) version 2 applications use the information provided in this OID to establish a relation between the NIC’s hardware clock and a system clock.

NDIS handles the OID_TIMESTAMP_CAPABILITY and OID_TIMESTAMP_GET_CROSSTIMESTAMP OIDs based on the information that the miniport driver reported when it registered the timestamping capabilities and current configuration to the operating system.

The miniport driver completes the OID_TIMESTAMP_GET_CROSSTIMESTAMP OID. The miniport must support this OID if it sets the CrossTimestamp field to TRUE in the NDIS_TIMESTAMP_CAPABILITIES structure as part of the current configuration.

For more information on how the miniport driver reports the timestamping capabilities, see Reporting timestamping capabilities and current configuration.