[PATCH 3/9] ARM: MB86S7X: Add MCPM support

[Nicolas Pitre]

On Wed, 26 Nov 2014, Andy Green wrote:

> On 25 November 2014 at 22:24, Sudeep Holla <sudeep.holla at arm.com> wrote:
> 
> > So IIUC, you run Linux in non-secure mode, PSCI would be more suitable
> > than MCPM when you start thinking/implementing CPUIdle otherwise I think
> > you will end up duplicating some logic(last man and race management)
> > both in Linux as well as your secure firmware.
> 
> As I mentioned our secure firmware is not what you're imagining.
> 
> MCPM works very well for us.  Are you saying we can't use MCPM and
> must reimplement with PSCI on both sides?

I said it many times before: not everyone is willing to invest in the 
complexity trap implied by the firmware model as proposed by ARM.  This 
is a concrete example of that.  MCPM-like functionality is an order of 
magnitude simpler to debug and maintain when implemented on the 
easily-replaceable kernel side.


Nicolas