On Tue, Aug 18, 2020 at 02:19:40AM +0300, Vladimir Oltean wrote: > This API was introduced for 2 reasons: > > 1. Some hardware can emit PPS signals but not starting from arbitrary > absolute times, but rather phase-aligned to the beginning of a > second. We _could_ patch ts2phc to always specify a start time of > 0.000000000 to PTP_PEROUT_REQUEST, but in practice, we would never > know whether that would actually work with all in-tree PHC drivers. > So there was a need for a new flag that only specifies the phase of > the periodic signal, and not the absolute start time. > > 2. Some hardware can, rather unfortunately, not distinguish between a > rising and a falling extts edge. And, since whatever rises also has > to fall before rising again, the strategy in ts2phc is to set a > 'large' pulse width (half the period) and ignore the extts event > corresponding to the mid-way between one second and another. This is > all fine, but currently, ts2phc.pulsewidth is a read-only property in > the config file. The kernel is not instructed in any way to use this > value, it is simply that must be configured based on prior knowledge > of the PHC's implementation. This API changes that. > > The introduction of a phase adjustment for the master PHC means we have > to adjust our approximation of the precise perout timestamp. We put that > code into a common function and convert all call sites to call that. We > also need to do the same thing for the edge ignoring logic.
If I am not mistaken, this change is really independent of the large re-factoring of this series. It could really get merged right away, or if that is too much work, as a follow on patch, after this series gets merged. Thanks, Richard _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
