On Tue, 20 Sep 2016, Thomas Gleixner wrote: > I think the whole approach is wrong because it makes the PTP split at the > wrong level. > > Currently we have: > > DRIVER_X > tristate "Driver X" > select PTP > > In order to make POSIX_CLOCK configurable we should have > > PTP > tristate "PTP" > select POSIX_CLOCK > > Now if you want to distangle PTP from a driver then you split it at the > driver level and not at the PTP level: > > DRIVER_X > tristate "Driver X" > > DRIVER_X_PTP > bool "Enable PTP support" > default y if !MAKE_IT_TINY > depends on DRIVER_X > select PTP > > We have already drivers following that scheme. That way you make the PTP > support in the driver conditional on DRIVER_X_PTP and have no hassle with > modules and dependencies.
I beg to disagree. There are way more drivers than subsystems and if you had to go around unselecting all NIC drivers for CONFIG_ETHERNET to be turned off, and with CONFIG_ETHERNET=n you'd finally be able to turn networking off, then this would be a nightmare. IMHO it is much nicer for the poor user configuring the kernel to have a single configuration prompt for PTP support, and then have whatever driver that can provide a PTP clock just do it (or omit it) based on that single prompt. Prompting for PTP support for each individual ethernet driver is silly. Nicolas
