Re: [PATCH v1 01/10] spi: pxa2xx: Drop ACPI_PTR() and of_match_ptr()

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Daniel Mack <daniel@zonque.org>,
	Haojian Zhuang <haojian.zhuang@gmail.com>,
	Robert Jarzmik <robert.jarzmik@free.fr>,
	Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH v1 01/10] spi: pxa2xx: Drop ACPI_PTR() and of_match_ptr()
Date: Tue, 26 Mar 2024 22:04:43 +0200	[thread overview]
Message-ID: <ZgMqW6TSHYJ2NOPq@smile.fi.intel.com> (raw)
In-Reply-To: <a30da48d-f801-4d0a-9db7-9c9bb159ca6b@sirena.org.uk>

On Tue, Mar 26, 2024 at 07:32:47PM +0000, Mark Brown wrote:
> On Tue, Mar 26, 2024 at 09:20:05PM +0200, Andy Shevchenko wrote:
> 
> > For my knowledge there is none of the ACPI-based platform where CONFIG_ACPI
> > needs to be 'n' while having the real device (as per ACPI ID table) to be on.
> > That's why I answered purely from the compilation point of view.
> 
> I don't understand the relevance of that, and frankly can't make much
> sense of it.

It's relevant to the ID table presence at run-time. But it seems I wrongly got
your point (see below).

> > Personally I see that dependency more confusing than hinting about anything.
> 
> When you don't have a dependency in Kconfig then people get offered the
> device even if it is impossible for it to be useful on their platform.

There is currently a dependency among others PCI || ACPI || COMPILE_TEST

From the point of view of the real platforms it means that if there is
a PCI compiled we support PCI devices that use this "platform" driver.
Similar with ACPI.

What you want is to hide this in the menuconfig for the irrelevant platforms
which have PCI _or_ ACPI enabled, correct?

But if we add x86 dependency to that, it will drop the support for non-x86
ACPI-based platforms with this device. I have no clue what are those.

Yes, we may try to have ((PCI || ACPI) && X86) at the end, but I believe
this will have a good regression effect.

> The purpose of any || COMPILE_TEST dependency is to improve the
> usability of Kconfig.

Right, when I see FOO || COMPILE_TEST I interpret FOO as *functional*
dependency, meaning that without FOO the certain driver makes no sense
from functional point of view.

-- 
With Best Regards,
Andy Shevchenko