Re: [PATCH] build some drivers only when compile-testing

Hi,

On 22/05/13 12:18, Jiri Slaby wrote:

Some drivers can be built on more platforms than they run on. This
causes users and distributors packaging burden when they have to
manually deselect some drivers from their allmodconfigs. Or sometimes
it is even impossible to disable the drivers without patching the
kernel.

Introduce a new config option COMPILE_TEST and make all those drivers
to depend on the platform they run on, or on the COMPILE_TEST option.
Now, when users/distributors choose COMPILE_TEST=n they will not have
the drivers in their allmodconfig setups, but developers still can
compile-test them with COMPILE_TEST=y.

Now the drivers where we use this new option:
* PTP_1588_CLOCK_PCH: The PCH EG20T is only compatible with Intel Atom
  processors so it should depend on x86.
* FB_GEODE: Geode is 32-bit only so only enable it for X86_32.
* USB_CHIPIDEA_IMX: The OF_DEVICE dependency will be met on powerpc
  systems -- which do not actually support the hardware via that
  method.

I had this exact same idea some time ago. The mail below contains some
of my reasoning for this:

http://comments.gmane.org/gmane.linux.kbuild.devel/9829

I proposed a new Kconfig keyword, but Sam was quite against it as the
Kconfig language already does what is required.

 Tomi