Re: [PATCH v2 2/5] ARM: mstar: Add machine for MStar/Sigmastar infinity/mercury family ARMv7 SoCs

[Daniel Palmer]

Hi Andreas,

On Thu, 11 Jun 2020 at 21:58, Andreas FÃrber <afaerber@xxxxxxx> wrote:

> You call the dir mach-mstar, but name the Kconfig ARCH_MSTARV7. I had
> previously been asked to just use the vendor name, so this should
> probably be just ARCH_MSTAR. Outside arch/arm/ you can then use ARM &&
> ARCH_MSTAR condition to make things 32-bit only, allowing to reuse
> ARCH_MSTAR for arm64 or whatever.

The ARM9 MStar chips before they switched to a common ARMv7 base aren't directly
compatible so I thought there should be some distinction there. I
doubt anyone will do it
but I made the directory mach-mstar so potentially someone could add
machine support
for the older stuff to without having more directories.

> > +     bool "MStar/Sigmastar ARMv7 SoC Support"
> > +     depends on ARCH_MULTI_V7
> > +     select ARM_GIC
> > +     select ARM_HEAVY_MB
> > +     help
> > +       Support for newer MStar/Sigmastar SoC families that are
> > +       based on ARMv7 cores like the Cortex A7 and share the same
> > +       basic hardware like the infinity and mercury series.
> > +
> > +if ARCH_MSTARV7
> > +
> > +config MACH_INFINITY
> > +     bool "MStar/Sigmastar infinity SoC support"
> > +     default ARCH_MSTARV7
> > +     help
> > +       Support for MStar/Sigmastar infinity IP camera SoCs.
> > +
> > +config MACH_MERCURY
> > +     bool "MStar/Sigmastar mercury SoC support"
> > +     default ARCH_MSTARV7
> > +     help
> > +       Support for MStar/Sigmastar mercury dash camera SoCs.
> > +       Note that older Mercury2 SoCs are ARM9 based and not supported.
>
> Is this comment really helpful? This menu item would only seem to come
> up after having selected multi_v7, which kind of rules out ARM9.

The older mercury2 based chips seem to still be available and used in
drive recorders
that are on the market right now. The infinity series is all ARMv7 so
can be supported
but for the mercury series only the newer ones are ARMv7 so I thought
it was worth
mentioning that "mercury SoC support" doesn't mean all of them. I'll
take it out if you
think it's unnecessary.

> Consider adding mercury in a second step?

I'll think about that. I wanted to try to get a machine that isn't one
I'm personally making
into the series.

Cheers,

Daniel