Re: [PATCH RFC 1/5] kconfig: implement weak reverse-dependencies

From: Richard Cochran
Date: Thu Mar 21 2013 - 07:43:28 EST

On Thu, Mar 21, 2013 at 03:06:11PM +0400, Konstantin Khlebnikov wrote:
> As I see this technology requires special dedicated server in the local
> network, thus it's unusable in most situations. But it starts working
> without any actions from the user (please fix me if I'm wrong).

Perhaps you don't have a very clear picture of how this PTP stuff
works. Even when the PHC and time stamping code is compiled in, it
does *not* start working unless the end user turns it on, via the

See: Documentation/networking/timestamping.txt

> Thus this code enables some rarely used parts of hardware.
> After seeing several weird bugs in ethernet devices I prefer to
> keep unused/unwanted features off.

Just compiling drivers into kernel does not really change the behavior
of the hardware. The only drawback I know of is that it adds (minimal)
overhead into the packet processing paths, but that is a software

I don't mean to start a big discussion here. The question of whether
to have PHC support a compile time option should be discussed on the
netdev list (added on CC just in case).


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