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

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 24 Sept 2025 at 13:41, Jon Hunter <jonathanh@nvidia.com> wrote:
>
> Hi Ulf,
>
> On 03/09/2025 13:33, Jon Hunter wrote:
>
> ...
>
> >>> Following this change I am seeing the following warning on our Tegra194
> >>> devices ...
> >>>
> >>>    WARNING KERN tegra-bpmp bpmp: sync_state() pending due to
> >>> 17000000.gpu
> >>>    WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 3960000.cec
> >>>    WARNING KERN tegra-bpmp bpmp: sync_state() pending due to
> >>> 15380000.nvjpg
> >>>    WARNING KERN tegra-bpmp bpmp: sync_state() pending due to
> >>> 154c0000.nvenc
> >>>    WARNING KERN tegra-bpmp bpmp: sync_state() pending due to
> >>> 15a80000.nvenc
> >>>
> >>> Per your change [0], the 'GENPD_FLAG_NO_SYNC_STATE' is set for Tegra
> >>> and so should Tegra be using of_genpd_sync_state() by default?
> >>
> >> This is a different power-domain provider (bpmp) in
> >> drivers/firmware/tegra/bpmp.c and
> >> drivers/pmdomain/tegra/powergate-bpmp.c.
> >>
> >> For the bpmp we don't need GENPD_FLAG_NO_SYNC_STATE, as the
> >> power-domain provider is described along with the
> >> "nvidia,tegra186-bpmp" compatible string. In the other case
> >> (drivers/soc/tegra/pmc.c) the "core-domain" and "powergates" are
> >> described through child-nodes, while ->sync_state() is managed by the
> >> parent-device-node.
> >>
> >> In the bpmp case there is no ->sync_state() callback assigned, which
> >> means genpd decides to assign a default one.
> >>
> >> The reason for the warnings above is because we are still waiting for
> >> those devices to be probed, hence the ->sync_state() callback is still
> >> waiting to be invoked. Enforcing ->sync_state() callback to be invoked
> >> can be done via user-space if that is needed.
> >>
> >> Did that make sense?
> >
> > Sorry for the delay, I was on vacation. Yes makes sense and drivers for
> > some of the above drivers are not yet upstreamed to mainline and so this
> > would be expected for now.
>
>
> 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 seems a bit noisy given that these do
> eventually probe OK. I am wondering if this should be more of a
> dev_info() or dev_dbg() print?

Yes, I agree. We have had similar reports for other platforms too.

I intend to send a patch for this in the next day or so.

Kind regards
Uffe