[PATCH 1/4] ARM: dts: augment Ux500 to use DT cpufreq

Linus Walleij
2017-08-13T12:23:10Z

On Fri, Aug 11, 2017 at 7:15 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:

> For example, below will fail cpufreq on your board. You can try that
> to make sure I am not dreaming.
>
> - Compile cpufreq-dt as a module.
> - Boot the board.
> - Offline CPU0 (i.e. Keep only CPU1 online).
> - Boom, cpufreq failed.
>
> This will happen because the CPU1 doesn't have the operating-points
> and other properties. We should have them in all the CPUs.

I don't think that will be a problem because CPU0 cannot be
taken offline on this system.

arch/arm/mach-ux500/platsmp.c surely only contain code to take
CPU1 online/offline.

At sleep, the BIOS/ROM handles taking down/up CPU0 so from
Linux' point of view that CPU is always online.

But I will look a bit closer and check.

This approach comes from the OMAP DT OPPs which also look like
this (and this system is similar).

Yours,
Linus Walleij