Re: [PATCH v3 0/2] ptp: split non-host-disciplined PHC drivers into a dedicated subdirectory

[Wen Gu]

On 2026/6/30 18:57, David Woodhouse wrote:
> On Tue, 2026-06-30 at 11:15 +0800, Wen Gu wrote:
>
> I was thinking we'd move them to drivers/phc, and simplify them as we do.
>
> Most of them are just a lot of PTP driver boilerplate, wrapping around
> one central function like
>
> static int vmclock_get_crosststamp(struct vmclock_state *st,
>                                     struct ptp_system_timestamp *sts,
>                                     struct system_counterval_t *system_counter,
>                                     struct timespec64 *tspec)
>
> ...which is called with different permutations of arguments depending
> on the actual PTP call.
>
> I was thinking of reducing the duplication and having the PHC drivers
> provide *only* that central function. Let the common PHC code provide
> the interface to PTP (as well as to core timekeeping, for setting the
> clock at boot, for timekeeping_set_reference() in the vmclock case, and
> perhaps even for a PPS-like discipline from other clocks).
>
> Here's a *very* hastily thrown together proof of concept; utterly
> untested and AI-produced, and I've only given it the bare minimum of
> oversight thus far (I have been meaning to do this for weeks but other
> things have taken precedence so far)...
>
> https://git.infradead.org/?p=linux-phc.git;a=shortlog;h=refs/heads/next

Thanks for the POC. I've looked over it and agree this is a cleaner
approach overall. The v3 was meant as an interim step, but given the POC
it makes more sense to go straight to drivers/phc.

I'm happy to adapt the Alibaba CIPU PHC driver to the new framework
once it's in place, and glad to help along the way if needed.