[PATCH RESEND 06/11] Revert "x86/geode: enable X86_INTEL_LPSS to select PINCTRL"

[Elliott Mitchell]

On Wed, Dec 13, 2023 at 01:59:07PM +0100, Martin Schiller wrote:
> On 2023-12-13 02:45, Elliott Mitchell wrote:
> > 
> > No idea, I wasn't able to find very much information when I looked at
> > this.
> > 
> > I did find:
> > https://lists.openwrt.org/pipermail/openwrt-devel/2018-August/019479.html
> > 
> > This doesn't tell me what platform Martin Schiller was trying for.
> > 17f30bfcf7 makes me suspect Martin Schiller was simply trying to do 
> > this
> > to all x86 platforms and didn't realize geode was a specialized target.
> > 
> > Alternatively Martin Schiller may have been trying to use a MCP23S08 on 
> > a
> > Geode processor.  Unfortunately using CONFIG_X86_INTEL_LPSS is a 
> > bizzare
> > choice since CONFIG_X86_AMD_PLATFORM_DEVICE has fewer side-effects and
> > then current Geodes were AMD processors.
> > 
> > With sparse information the former is my present belief.  Is anyone
> > reading this list using a Geode processor with a MCP23S08?  Otherwise 
> > my
> > present belief is only people with Intel x86 processors are interested 
> > in
> > the MCP23S08.

> The problem was and is that the PINCTRL subsystem can only be used on 
> x86
> platforms if either X86_INTEL_LPSS or X86_AMD_PLATFORM_DEVICE is 
> activated.
> I no longer know why I chose the former at the time.

Which leaves me suspecting the reason was you had a computer with a
processor from Intel.

> X86_AMD_PLATFORM_DEVICE is now activated for x86/generic and x86/64.
> 
>  From my point of view, we can deactivate X86_INTEL_LPSS if no one else
> need it.

Seeing how Xiaopo Zhang submitted patches to enable them, I assume at
least 1 other person used them on x86/64 at some point.

What situation/hardware were YOU using CONFIG_PINCTRL for?

Were you using CONFIG_PINCTRL on a desktop which had an Intel processor?

Were you using CONFIG_PINCTRL on a system which had a Geode processor?

If someone out there is actively using CONFIG_PINCTRL on a system with a
Geode processor, I would disable CONFIG_X86_INTEL_LPSS and enable
CONFIG_X86_AMD_PLATFORM_DEVICE.  The reason is both options select
CONFIG_COMMON_CLK and CONFIG_PINCTRL, but CONFIG_X86_INTEL_LPSS
additionally selects CONFIG_IOSF_MBI (less bloat).

If my belief no one is using CONFIG_PINCTRL on a Geode platform is
correct, then the original patch is correct.  From examination of the
Linux kernel source, I believe none of Geode's normal peripherals go
through the PINCTRL subsystem.

Problem is too few people have systems with Geode processors in use, so
support is difficult.


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