Messages in this thread | | | Date | Tue, 31 May 2022 13:25:52 -0700 | Subject | Re: Kconfig rules (depends, imply) | From | Randy Dunlap <> |
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Hi--
On 5/31/22 05:14, Muni Sekhar wrote: > Hi all, > > menuconfig SOUNDWIRE > tristate "SoundWire support" > depends on ACPI || OF > > "depends on ACPI || OF" mean, SOUNDWIRE depends on both ACPI and OF modules? >
"||" is logical OR, so SOUNDWIRE depends on either ACPI or OF (or both of them can be enabled).
> > config SOUNDWIRE_QCOM > tristate "Qualcomm SoundWire Master driver" > imply SLIMBUS > > What does "imply SLIMBUS" mean?
See Documentation/kbuild/kconfig-language.rst:
- weak reverse dependencies: "imply" <symbol> ["if" <expr>]
This is similar to "select" as it enforces a lower limit on another symbol except that the "implied" symbol's value may still be set to n from a direct dependency or with a visible prompt.
So (in your example) SLIMBUS is desired but not required. That means that the code that is built for SOUNDWIRE_QCOM probably needs to use IS_REACHABLE(CONFIG_SLIMBUS) to see if that SLIMBUS code is available at build time.
HTH. -- ~Randy
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