Messages in this thread | | | Date | Mon, 27 Jul 2020 19:12:32 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH v3 2/2] mtd: rawnand: ingenic: Limit MTD_NAND_JZ4780 to architecture only |
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Le lun. 27 juil. 2020 à 19:03, Krzysztof Kozlowski <krzk@kernel.org> a écrit : > On Mon, Jul 27, 2020 at 09:55:54AM +0200, Arnd Bergmann wrote: >> On Sun, Jul 26, 2020 at 6:20 PM Paul Cercueil >> <paul@crapouillou.net> wrote: >> > Le dim. 26 juil. 2020 à 18:15, Krzysztof Kozlowski >> <krzk@kernel.org> a écrit : >> > > On Sun, Jul 26, 2020 at 06:12:27PM +0200, Paul Cercueil wrote: >> > >> Le dim. 26 juil. 2020 à 18:06, Krzysztof Kozlowski >> <krzk@kernel.org> a écrit >> > >> > > OK, that's true. Anyway, I don't have strong opinion on any of >> this. I >> > > just followed Arnd's hint. >> > > >> > > For the memory driver (and MTD NAND as well) which one you >> prefer: >> > > 1. >> https://lore.kernel.org/lkml/20200724074038.5597-6-krzk@kernel.org/ >> > > 2. depends on MACH_INGENIC || MIPS_GENERIC || COMPILE_TEST >> > > >> > > ? >> > >> > I'd say a slightly modified #1. The driver shouldn't be "default >> y" in >> > the first place, so the patch could be to disable it by default. >> >> If it defaults to 'n' even for MACH_INGENIC, you may have to enable >> it in the four defconfig files for these machines to avoid >> surprises. > > Exactly. Nothing else selects JZ4780_NEMC, so either we keep default y > ("if MACH_INGENIC || MIPS_GENERIC"), or you select it directly from > MACH_INGENIC/MIPS_GENERIC. > > A related question is how essential are these drivers? At least for > ARM > platforms, all essential SoC blocks/IPs are selected by default, if > support for chosen SoC is enabled. Only non-essential stuff is left, > e.g. DRM, cpufreq, devfreq, ADC, crypto, video, USB, eMMC (although > one > could argue that it is essential), IOMMU.
They are only used for NAND access, which is not really essential (some boards only use MMC storage), that's why I said they shouldn't have been enabled by default in the first place.
-Paul
> >> > And when the Ingenic code is merged into the MIPS generic >> framework, I'll >> > send a set of patches to change all driver dependencies on MIPS to >> > MIPS_GENERIC. >> >> The way we do it on Arm, the machine Kconfig identifiers stay around >> even for multiplatform targets (which now make up basically actively >> maintained machines). >> >> I don't think it makes any sense for a driver to depend on >> MIPS_GENERIC: >> either it is a generic driver that should always be visible or it >> is specific >> to a set of SoCs and should depend on some corresponding vendor >> specific identifiers. > > If support for Ingenic is provided also by MIPS_GENERIC (without > selecting MACH_INGENIC), then it makes sense. This would be just a > different way than ARM of building multi-platform kernel. > > Best regards, > Krzysztof
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