From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 1 Aug 2018 10:10:27 +0100 Subject: [PATCH 6/6] arm64: enable RapidIO menu in Kconfig In-Reply-To: References: <20180730225035.28365-1-acolin@isi.edu> <20180730225035.28365-7-acolin@isi.edu> <20180731084143.GA4680@arm.com> Message-ID: <20180801091027.GC14438@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > >>>Cc: Russell King > >>>Cc: John Paul Walters > >>>Cc: linux-arm-kernel at lists.infradead.org > >>>Cc: linux-kernel at vger.kernel.org, > >>>Signed-off-by: Alexei Colin > >>>--- > >>>? arch/arm64/Kconfig | 2 ++ > >>>? 1 file changed, 2 insertions(+) > >> > >>Thanks, this looks much cleaner than before: > >> > >>Acked-by: Will Deacon > >> > >>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