On Thu, Oct 22, 2020 at 01:11:40PM +0200, Christian Eggers wrote: > Hi Vladimir, > > On Thursday, 22 October 2020, 12:50:14 CEST, Vladimir Oltean wrote: > after applying the RX timestamp correctly to the correction field (shifting > the nanoseconds by 16), That modification should have been done anyway, since the unit of measurement for correctionField is scaled ppb (48 bits nanoseconds, 16 bits scaled nanoseconds), and not nanoseconds. > it seems that "moving" the timestamp back to the tail tag on TX is not > required anymore. Keeping the RX timestamp simply in the correction > field (negative value), works fine now. So this halves the effort in > the tag_ksz driver. Ok, this makes sense. Depending on what Richard responds, it now looks like the cleanest approach would be to move your implementation that is currently in ksz9477_update_ptp_correction_field() into a generic function called static inline void ptp_onestep_p2p_move_t2_to_correction(struct sk_buff *skb, unsigned int ptp_type, struct ptp_header *ptp_header, ktime_t t2) You should then clearly document that this function is needed for hardware capable of one-step P2P that does not already modify the correctionField of Pdelay_Req event messages on ingress.
