Re: [PATCH v3) posix-timers: make it configurable

From: Nicolas Pitre
Date: Thu Sep 15 2016 - 17:36:18 EST

On Thu, 15 Sep 2016, Josh Triplett wrote:

> On Thu, Sep 15, 2016 at 11:07:24PM +0200, Richard Cochran wrote:
> > On Thu, Sep 15, 2016 at 12:58:22PM -0700, John Stultz wrote:
> > > This doesn't look too bad.
> >
> > I disagree. It looks ugly. If tinification means sprinkling more and
> > more of these conditionals all over the place, then it is going to be
> > a tough sell.
> Looking at this particular patch, it does seem a bit much for the
> ability to have PTP without timers. That doesn't seem like a very
> likely combination. Handling that in Kconfig seems fine, unless there's
> a concrete use case for that combination.

I doubt there is. This is more for randconfig purposes or the like.

I suspect there is more of a case for having net drivers _without_ ptp
support. This could be implemented with a ptp_clock_register() stub
returning NULL when ptp is not configured. I didn't look at most
drivers but at least broadcom/tg3.c seems to be fine with such an

Alternatively, all those ethernet drivers currently selecting
PTP_1588_CLOCK could be banned from the kernel config when POSIX_TIMERS
is not selected.

What do people prefer?