Re: [PATCH v9 09/13] powercap: arm_scmi: Enable multiple constraints support

[Philip Radford <philip.radford@arm.com>]

On Thu, Oct 15, 2026 at 02:24:40PM +0100, Sudeep Holla wrote:
> On Wed, Sep 09, 2026 at 10:04:33PM +0000, Philip Radford wrote:
> > From: Cristian Marussi <cristian.marussi@arm.com>
> > 

Hi,

> > Initialize the domains with all the discovered available constraints,
> > making available multiple per-domain constraints when the platform has
> > advertised support for multiple concurrent power limits.
> > 
> > CC: "Rafael J. Wysocki" <rafael@kernel.org>
> > CC: linux-pm@vger.kernel.org
> > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> > [Philip: Amended Copyright]
> > Signed-off-by: Philip Radford <philip.radford@arm.com>
> > ---
> > V8->V9
> > - Added validation check to make sure powercap domain doesn't have too
> > many constraints
> > ---
> >  drivers/powercap/arm_scmi_powercap.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/powercap/arm_scmi_powercap.c b/drivers/powercap/arm_scmi_powercap.c
> > index 2d9370aaaf5d..bcd1ba0bde8c 100644
> > --- a/drivers/powercap/arm_scmi_powercap.c
> > +++ b/drivers/powercap/arm_scmi_powercap.c
> > @@ -2,7 +2,7 @@
> >  /*
> >   * SCMI Powercap support.
> >   *
> > - * Copyright (C) 2022 ARM Ltd.
> > + * Copyright (C) 2022-2026 ARM Ltd.
> >   */
> >  
> >  #include <linux/device.h>
> > @@ -491,7 +491,7 @@ static int scmi_powercap_register_zone(struct scmi_powercap_root *pr,
> >  
> >  	z = powercap_register_zone(&spz->zone, scmi_top_pcntrl, spz->info->name,
> >  				   parent ? &parent->zone : NULL,
> > -				   &zone_ops, 1, &constraint_ops);
> > +				   &zone_ops, spz->info->num_cpli, &constraint_ops);
> >  	if (!IS_ERR(z)) {
> >  		spz->height = scmi_powercap_get_zone_height(spz);
> >  		spz->registered = true;
> > @@ -649,6 +649,13 @@ static int scmi_powercap_probe(struct scmi_device *sdev)
> >  		 */
> >  		spz->info = powercap_ops->info_get(ph, i);
> >  
> > +		if (spz->info->num_cpli > MAX_CONSTRAINTS_PER_ZONE) {
> 
> Since MAX_CONSTRAINTS_PER_ZONE = 10 and our SCMI f/w can return upto 15,
> we may have to warn or clamp it to 10 or both.
> 

Noted. I will address this in the next version, thank you.

Regards,
Phil