[Linuxptp-users] Software Based Timestamps does not work

[Keller, J. E <jac...@in...>]

When enabling software based timestamps via the '-s' switch, the program switches to the faulty state instantly after transmitting a packet that should be timestamped because the software timestamp is never obtained. With further investigation, it turns out that software timestamping appears to be disabled. I tested with the kernel timestamping.c program, and indeed just selecting sof_timestamping_tx_software, sof_timestamping_rx_software and sof_timestamping_software does not return timestamps. The additional option of sof_timestampns must also be enabled. I would like to use software timestamping in order to connect ptp4l to a grandmaster clock as verification that the protocol implementation works with a known good PTP clock.

While the intention is for ptp4l to be used with hardware timestamping, there still is issue with software timestamping not working (for when the hardware doesn't support offloading)