Messages in this thread | | | Date | Wed, 07 Dec 2022 19:57:31 +0100 | From | "Arnd Bergmann" <> | Subject | Re: [PATCH v2] mux: remove the Kconfig question for the subsystem |
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On Wed, Dec 7, 2022, at 18:19, Randy Dunlap wrote: > On 12/7/22 00:41, Arnd Bergmann wrote: >> For the other subsystems I mentioned, there are occasionally >> problems with missing 'select' that tend to be a pain to find, >> compared to subsystems consistently using 'depends on', which >> show up as link failures in randconfig builds. > > I find that various drivers mixing the use of "select" and > "depends on" is problematic.
Agreed. Even just mixing 'select' with user-visible symbols is very confusing. The two sensible ways are either using user-visible options with 'depends on' or hidden options with 'select'.
> However, there was no answer for the original question: > How does a user enable the 4 Kconfig symbols in drivers/mux/Kconfig > if some other random driver has not selected MULTIPLEXER?
There is no need to enable any of them in this case, because the mux drivers are not usable by themselves.
> I.e.: > > config MUX_ADG792A > tristate "Analog Devices ADG792A/ADG792G Multiplexers" > > config MUX_ADGS1408 > tristate "Analog Devices ADGS1408/ADGS1409 Multiplexers" > > config MUX_GPIO > tristate "GPIO-controlled Multiplexer" > > config MUX_MMIO > tristate "MMIO/Regmap register bitfield-controlled Multiplexer" > > OK, MUX_MMIO is selected from some other drivers, but if that is not done, > how can the first 3 be enabled by a user?
They cannot, that is the entire point of hiding the subsystem when it is not used.
Arnd
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