On Friday 05 September 2014 15:22:46 Mark Rutland wrote:

quoted

A common pattern these days is to do dependencies like

arch/*/Kconfig:
      config ARCH_FOO
      bool "Enable support for Foo platform"
      help
        ...


drivers/*/Kconfig
      config SUBSYS_FOO
      bool "SUBSYS driver for Foo"
      depends on ARCH_FOO || COMPILE_TEST
      depends on OF && REGULATOR && GENERIC_PHY # or whatever

Russell's comments w.r.t. Kconfig warnings when config names change
still holds regardless of select vs depends on.

Yes, that's what I wrote in my reply as well.

quoted

That way we can enable everything in the defconfig, but someone
who likes to build a more specialized kernel can disable the
other platforms and won't get the drivers that are specific to
those.

I personally think this is a bit more verbose than what we need, but
I don't strongly object doing it that way.

You'd still be able to do this without ARCH_FOO, though you would need
to know which drivers are necessary for a particular SoC. That seems to
be the way things are handled on x86; I don't recall having to select
support for specific machines there, just the individual drivers.

The main difference is that there are very few drivers on x86 that are
specific to one of the two chip makers. Almost everything is a PCI
device that can actually be plugged in anywhere.

On ARM64 there is going to be a lot of stuff that really makes sense
only for one of the 50 licensees.

	Arnd