[PATCH v3 20/24] pmdomain: core: Default to use of_genpd_sync_state() for genpd providers

[Ulf Hansson]

On Fri, 26 Sept 2025 at 17:32, Jon Hunter <jonathanh at nvidia.com> wrote:
>
>
> On 25/09/2025 23:31, Saravana Kannan wrote:
>
> ...
>
> >> I have been doing more testing and do see a lot of "tegra-bpmp bpmp:
> >> sync_state() pending due to" on our platforms for basically are driver
> >> that is built as a module.
> >
> > It being "built as a module" is not reason enough for this warning to
> > happen though. One of the main points of fw_devlink is for things to
> > work just as well with modules.
> >
> > In this particular system, do you never plan to load the modules? Or
> > is the module load just missing this timeout by a few seconds or
> > something?
>
> We absolutely do load the drivers. Initially, I observed cases where
> drivers are missing, but doing more testing with the necessary drivers
> present, I still see such messages. A lot of our test infrastructure is
> set up to use NFS for mounting to the rootfs and so I am wondering if
> that can also be a factor?
>
> > If these can be turned off, why not turn these off using the sysfs
> > file or the timeout commandline option to turn them off? You are
> > burning power by leaving these on. A warning seems appropriate to me.
>
> Again the drivers get loaded, so that shouldn't be the case.
>

I realized that we also have an orthogonal, but related problem.

In fact, the genpd in question actually may already have been
powered-off, completely defeating the purpose of the printed warning
that we are discussing.

In genpd we enable the ->sync_state() support, no matter whether the
genpd is powered-on or powered-off at initialization. Although, it's
only when a genpd is powered-on at init, when we prevent it from being
powered-off until the ->sync_state() callback gets invoked. Ideally,
we should be able to skip enabling the ->sync_state() support for
genpd in these cases, possibly silencing some of these prints. I will
have a look at this and get back to you.

Kind regards
Uffe