On Sun, Jan 22, 2023 at 06:48:49PM -0800, Rahul Rameshbabu wrote:

Another question then is can adjtime/ADJ_SETOFFSET make use of this
servo implementation on the device or is there a strict expectation that
adjtime/ADJ_SETOFFSET is purely a function that adds the offset to the
current current time?

ADJ_SETOFFSET == clock_settime.  Drivers should set the time
immediately.

If adjphase is implemented by a driver, should
ADJ_SETOFFSET try to make use of it in the ptp stack if the offset
provided is supported by the adjphase implementation?

No.


BTW, as mentioned in the thread, the KernelDoc is really, really bad:

 * @adjphase:  Adjusts the phase offset of the hardware clock.
 *             parameter delta: Desired change in nanoseconds.

The change log is much better:

    ptp: Add adjphase function to support phase offset control.

    Adds adjust phase function to take advantage of a PHC
    clock's hardware filtering capability that uses phase offset
    control word instead of frequency offset control word.

So the Kernel Doc should say something like:

 * @adjphase:  Feeds the given phase offset into the hardware clock's servo.
 *             parameter delta: Measured phase offset in nanoseconds.

Thanks,
Richard