Re: [PATCH 2/3] pmdomain: Add support for system-suspend-only states

[Ulf Hansson]

On Tue, Oct 6, 2026 at 11:15 AM Sudeep Holla <sudeep.holla@xxxxxxxxxx> wrote:
>
> On Mon, Oct 05, 2026 at 08:59:43PM +0530, Maulik Shah wrote:
> > Some domain idle states require system-wide coordination and should not be
> > selected during regular CPU idle. However those states remain valid for
> > system-wide suspend like s2idle.
> >
> > Add a per-state system_state boolean and populate it from the system-state
> > property. Make the genpd governor skip these states during CPU idle. Leave
> > the system wide suspend path unchanged so s2idle can select them.
> >
>
> Instead of this I am thinking if we can QoS cpu latency setting and block
> system level states normally. Since s2idle is user driven, it should be
> controllable via user-space and we don't have to define bindings again
> if systems that use platform-coordinated needs this too. They may not
> use domain-idle-states.

Even if we likely could make that work, it's seems not correct to rely
on userspace to make the kernel to pick the correct idle state, while
the decision should be based on the characteristics of the HW.

In regards to PSCI PC mode, I believe we should consider adding the
similar DT property for the arm,idle-state binding and make a
corresponding change for the regular CPUIdle path/governors. Although,
it doesn't necessarily need to be part of the $subject series. I would
 be fine if that is handled later on too.

Kind regards
Uffe