PTP Clock Support

configname: CONFIG_IXGBE_PTP

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Ethernet driver support
└─>PTP Clock Support
In linux kernel since version 3.5 (release Date: 2012-07-21)  
Say Y here if you want support for 1588 Timestamping with a
PHC device, using the PTP 1588 Clock support. This is
required to enable timestamping support for the device.

If unsure, say N.