On Tue, Jul 31, 2018 at 04:29:56PM -0400, Alex Bounine wrote: > On 2018-07-31 08:54 AM, Alex Bounine wrote: > >On 2018-07-31 04:41 AM, Will Deacon wrote: > >>On Mon, Jul 30, 2018 at 06:50:34PM -0400, Alexei Colin wrote: > >>>Platforms with a PCI bus will be offered the RapidIO menu since they may > >>>be want support for a RapidIO PCI device. Platforms without a PCI bus > >>>that might include a RapidIO IP block will need to "select HAS_RAPIDIO" > >>>in the platform-/machine-specific "config ARCH_*" Kconfig entry. > >>> > >>>Tested that kernel builds for arm64 with RapidIO subsystem and > >>>switch drivers enabled, also that the modules load successfully > >>>on a custom Aarch64 Qemu model. > >>> > >>>Cc: Andrew Morton <a...@linux-foundation.org> > >>>Cc: Russell King <li...@armlinux.org.uk> > >>>Cc: John Paul Walters <jwalt...@isi.edu> > >>>Cc: linux-arm-ker...@lists.infradead.org > >>>Cc: linux-kernel@vger.kernel.org, > >>>Signed-off-by: Alexei Colin <aco...@isi.edu> > >>>--- > >>> arch/arm64/Kconfig | 2 ++ > >>> 1 file changed, 2 insertions(+) > >> > >>Thanks, this looks much cleaner than before: > >> > >>Acked-by: Will Deacon <will.dea...@arm.com> > >> > >>The only thing I'm not sure about is why we don't just select HAS_RAPIDIO > >>unconditionally in the arm64 Kconfig. Does selecting only that option > >>actually pull in new code to the build? > >> > >HAS_RAPIDIO option is intended for SOCs that have built in SRIO > >controllers, like TI KeyStoneII or FPGAs. Because RapidIO subsystem core > >is required during RapidIO port driver initialization, having separate > >option allows us to control available build options for RapidIO core and > >port driver (bool vs. tristate) and disable module option if port driver > >is configured as built-in. > > I am thinking about where HAS_RAPIDIO option can be set for arm64 branch. > Having it set globally is too broad. For example we have Xilinx Zinq US > board with SRIO IP on it. Having it globally in arm64 branch - bad. Probably > having it set in drivers/soc/... is the best place.
Why is selecting HAS_RAPIDIO globally a bad thing to do? The way these normally work is, if some subsystem requires arch support, then there's an ARCH_HAS_xxxx option which the architecture selects when it implements that support. Once you've enabled that, then that allows other sub-options to be selected, such as specific drivers or what-not. Look at the Kconfig files under drivers/soc/ -- you don't see anybody selecting ARCH_HAS_* options. Now, if HAS_RAPIDIO alone is pulling in a whole load of code to the build, then it sounds like a misnomer. Confused. Will
