Re: [PATCH v6 4/6] clk: samsung: add Exynos ACPM clock driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 11/11/2025 02:39, Stephen Boyd wrote:
> Quoting Tudor Ambarus (2025-10-20 00:45:58)
>>
>>
>> On 10/20/25 7:54 AM, Krzysztof Kozlowski wrote:
>>>> diff --git a/drivers/clk/samsung/Kconfig b/drivers/clk/samsung/Kconfig
>>>> index 76a494e95027af26272e30876a87ac293bd56dfa..70a8b82a0136b4d0213d8ff95e029c52436e5c7f 100644
>>>> --- a/drivers/clk/samsung/Kconfig
>>>> +++ b/drivers/clk/samsung/Kconfig
>>>> @@ -95,6 +95,16 @@ config EXYNOS_CLKOUT
>>>>        status of the certains clocks from SoC, but it could also be tied to
>>>>        other devices as an input clock.
>>>>  
>>>> +config EXYNOS_ACPM_CLK
>>>> +    tristate "Clock driver controlled via ACPM interface"
>>>> +    depends on EXYNOS_ACPM_PROTOCOL || (COMPILE_TEST && !EXYNOS_ACPM_PROTOCOL)
>>>
>>> I merged the patches but I don't get why we are not enabling it by
>>> default, just like every other clock driver. What is so special here?
>>
>> Thanks! Are you referring to the depends on line? I needed it otherwise
>> on randconfigs where COMPILE_TEST=y and EXYNOS_ACPM_PROTOCOL=n I get:
>>
>> ERROR: modpost: "devm_acpm_get_by_node" [drivers/clk/samsung/clk-acpm.ko] undefined!
>>
> 
> I don't understand that part. The depends on statement "COMPILE_TEST &&
> !EXYNOS_ACPM_PROTOCOL" is equivalent to COMPILE_TEST=y and
> EXYNOS_ACPM_PROTOCOL=n, so are you trying to avoid
> EXYNOS_ACPM_PROTOCOL=y when COMPILE_TEST=y?

This is the standard kconfig module dependency to avoid having built-in
when other is module:
EXYNOS_ACPM_PROTOCOL || !EXYNOS_ACPM_PROTOCOL
It is used everywhere and already documented.

Now, the only difference here is that !EXYNOS_ACPM_PROTOCOL is actually
not meaningful for the driver, because it is not an optional dependency,
thus we allow this only for compile testing, therefore:
|| COMPILE_TEST && !EXYNOS_ACPM_PROTOCOL.


Best regards,
Krzysztof