Re: [PATCH] HISI LPC: Add Kconfig MFD_CORE dependency

[John Garry]

On 19/04/2018 13:00, Arnd Bergmann wrote:
> On Thu, Apr 19, 2018 at 1:55 PM, John Garry <john.garry@xxxxxxxxxx> wrote:
> > For ACPI support of the HiSilicon LPC driver we depend
> > on MFD_CORE config.
> >
> > Currently the HiSi LPC Kconfig entry does not define this
> > dependency, so add it.
> >
> > Fixes: e0aa1563f894 ("HISI LPC: Add ACPI support")
> > Reported-and-tested-by: Tan Xiaojun <tanxiaojun@xxxxxxxxxx>
> > Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
>
> Can you explain the specific dependency? Normally MFD_CORE gets
> selected by an MFD driver but not other drivers.

For each device on the LPC bus we create an MFD.

The reason we do this is that we need to set the resources of the 
derived MFD, as we should not modify the original ACPI device created in 
ACPI scan. Details are in the log for e0aa1563f894.

Shall I update commit message updated with this info? Or were you just 
interested in the motivation for using MFD?

Thanks,
John

>        Arnd
>
> .