Check PTP_SYS_OFFSET ioctl

Check that PTP_SYS_OFFSET ioctl can be used to obtain samples of PTP device time and system time at the same moment.

Scenarios: X3-PTP006.

  1. Find out PTP device associated with the IUT interface, call open() to get its FD.

  2. Call ioctl (PTP_SYS_OFFSET) on the PTP device FD asking for n_samples samples.

  3. Compute average difference between consecutive pairs of timestamps obtained from PTP_SYS_OFFSET. Check that difference between every such pair is very close to that average.

  4. Estimate offset between PTP and system clocks with help of two consecutive clock_gettime() calls. Check that this estimate is close to the average difference between timestamps pairs obtained from PTP_SYS_OFFSET.

Yurij Plotnikov Yurij.Plotnikov@arknetworks.am

Parameters:

env

Testing environment:

n_samples

How many samples to request from PTP_SYS_OFFSET