23.2. Using PTP
23.2. Using PTP In order to use PTP , the kernel network driver for the intended interface has to support either software or hardware time stamping capabilities. 23.2.1. Checking for Driver and Hardware Support In addition to hardware time stamping support being present in the driver, the NIC must also be capable of supporting this functionality in the physical hardware. The best way to verify the time stamping capabilities of a particular driver and NIC is to use the ethtool utility to query the interface as follows: Where eth3 is the interface you want to check. For software time stamping support, the parameters list should include: SOF_TIMESTAMPING_SOFTWARE SOF_TIMESTAMPING_TX_SOFTWARE SOF_TIMESTAMPING_RX_SOFTWARE For hardware time stamping support, the parameters list should include: SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_TX_HARDWARE SOF_TIMESTAMPING_RX_HARDWARE
~]# ethtool -T eth3 Time stamping parameters for eth3: Capabilities: hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE) software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE) hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE) software-receive (SOF_TIMESTAMPING_RX_SOFTWARE) software-system-clock (SOF_TIMESTAMPING_SOFTWARE) hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE) PTP Hardware Clock: 0 Hardware Transmit Timestamp Modes: off (HWTSTAMP_TX_OFF) on (HWTSTAMP_TX_ON) Hardware Receive Filter Modes: none (HWTSTAMP_FILTER_NONE) all (HWTSTAMP_FILTER_ALL)