linux-kernel - Re: [PATCH 4/4] platform/x86: pmc_atom: make the PMC driver actually unselectable

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Date:   Thu, 28 Apr 2022 13:20:05 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Paul Gortmaker <paul.gortmaker@...driver.com>
Cc:     linux-kernel@...r.kernel.org,
        Aubrey Li <aubrey.li@...ux.intel.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Len Brown <lenb@...nel.org>, linux-acpi@...r.kernel.org,
        Mark Gross <markgross@...nel.org>,
        platform-driver-x86@...r.kernel.org,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH 4/4] platform/x86: pmc_atom: make the PMC driver actually
 unselectable

On Thu, Apr 28, 2022 at 02:24:30AM -0400, Paul Gortmaker wrote:
> This caught my eye when I saw it was def_bool and hence largely
> pointless to have a Kconfig for it at all.
> 
> Yet there is no reason why you shouldn't be able to opt out of Atom
> platform support if you only care about desktop and server class CPUs.
> 
> It was introduced as def_bool, but there is no obvious reason as to why
> it was forcibly built-in for everyone, other than LPSS implicitly
> relying on it (which is now fixed).  So here we fix up the Kconfig and
> open the door for people to opt out.
> 
> Since putting "default y" on anything that isn't absolutely essential is
> generally frowned upon, I made the default be CONFIG_MATOM.  People who
> use "make oldconfig" or similar won't notice any difference.
> 
> The two "unchanged" lines for PCI and COMMON_CLK appear in the diff from
> fixing a whitespace issue that somehow managed to live on despite being
> moved between two different Kconfig files since its introduction.

>  config PMC_ATOM
> -       def_bool y
> -       depends on PCI
> -       select COMMON_CLK
> +	bool "Intel Atom SOC Power Management Controller driver"

s/SOC/SoC/ here and everywhere else in this patch.

> +	default MATOM
> +	depends on PCI
> +	select COMMON_CLK
> +	help
> +	  This enables support for the Atom SOC Power Management Controller
> +	  driver, and associated platform clocks.  If you intend to boot this

One space is enough.

> +	  kernel on platforms with an intel Atom CPU, say Y here.

Please, list the Atoms that really need this, for example, Broxton doesn't.

I believe the list should include (but not limited to):

	Intel Bay Trail
	Intel Braswell
	Intel Cherry Trail

-- 
With Best Regards,
Andy Shevchenko