Re: [PATCH 01/11] ARM: vexpress: use ARM_CPU_SUSPEND if needed

Russell King - ARM Linux
2015-02-13T10:58:09Z

On Fri, Feb 13, 2015 at 10:37:16AM +0000, Liviu Dudau wrote:
> On Thu, Feb 12, 2015 at 07:42:33PM +0000, Arnd Bergmann wrote:
> > The vexpress tc2 power management code calls mcpm_loopback, which
> > is only available if ARM_CPU_SUSPEND is enabled, otherwise we
> > get a link error:
> >
> > arch/arm/mach-vexpress/built-in.o: In function `tc2_pm_init':
> > arch/arm/mach-vexpress/tc2_pm.c:389: undefined reference to `mcpm_loopback'
>
> Arnd,
>
> We are having reports of TC2 not booting with MCPM enabled. Lorenzo
> was investigating this but then headed for Linaro Connect this week,
> so we don't have yet a resolution. Can this patch be postponed for
> a later -rc?

Why?

This patch isn't forcing MCPM to be enabled for Versatile Express.

* In order to build tc2_pm.c, MCPM must already be enabled (the
feature depends on MCPM in the Kconfig already)
* When this feature is enabled, the above link error occurs if
ARM_CPU_SUSPEND is not also enabled.

So, it is merely fixing the requirement that tc2_pm.c needs the CPU
suspend infrastructure, which in turn has no effect on whether MCPM
is enabled or not.

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