Re: [RFC PATCH 0/3] SCMI System Power Support

[Cristian Marussi <cristian.marussi@arm.com>]

On Wed, May 06, 2020 at 02:11:45PM -0500, Rob Herring wrote:
> On Thu, Apr 30, 2020 at 12:23 PM Cristian Marussi
> <Cristian.Marussi@arm.com> wrote:
> >
> > Hi Rob
> >
> > thanks for the feedback.
> 
> Plain text for maillists please.
> 
Yes I know, sorry, used wrong client by mistake.

> >
> > > On top of this a new SCMI driver has been developed which registers for
> > > ----
> > > such System Power notification and acts accordingly to satisfy such
> > > plaform system-state transition requests that can be of forceful or
> > > graceful kind.
> >
> > > I needed this 7 years ago. :) (hb_keys_notifier in
> > > arch/arm/mach-highbank/highbank.c)
> >
> > ...better later than never
> >
> > > Such alternative, if deemed worth, should clearly be configurable via DT
> > > (also in terms of which signals to use), BUT all of this work is not done
> > > in this series: and that's the reason for the RFC tag: does it make sense
> > > to add such a configurable additional option ?
> >
> > >Which process signal to use in DT? I don't think so.
> >
> > ... beside the awkward bad idea of mine of configuring it via DT
> > (which I'll drop possibly using modparams for this config), my question
> > was more about if it makes sense at all to have another alternative mechanism
> > (other than orderly_poweroof/reboot)) based on signals to gracefully ask userspace
> > to shutdown
> 
> gregkh will tell you no to module params.
> 
> If the signal is not standard, then we probably shouldn't go that route.
> 

Before this reply, I posted a v2 with alternative signal-method configurable by modparam;
it's anyway a small addition which I can easily remove in a v3.

Thanks

Cristian