On Thu, 31 Jul 2025 at 17:07, Jon Hunter [off-list ref] wrote:

Hi Ulf,

On 01/07/2025 12:47, Ulf Hansson wrote:

quoted

Unless the typical platform driver that act as genpd provider, has its own
->sync_state() callback implemented let's default to use
of_genpd_sync_state().

More precisely, while adding a genpd OF provider let's assign the
->sync_state() callback, in case the fwnode has a device and its driver
doesn't have the ->sync_state() set already. In this way the typical
platform driver doesn't need to assign ->sync_state(), unless it has some
additional things to manage beyond genpds.

Suggested-by: Saravana Kannan <redacted>
Tested-by: Hiago De Franco <redacted> # Colibri iMX8X
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # TI AM62A,Xilinx ZynqMP ZCU106
Signed-off-by: Ulf Hansson <redacted>
---
  drivers/pmdomain/core.c | 9 +++++++++
  1 file changed, 9 insertions(+)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index ca47f91b9e91..5cef6de60c72 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c

@@ -2600,6 +2600,11 @@ static bool genpd_present(const struct generic_pm_domain *genpd)
      return ret;
  }

+static void genpd_sync_state(struct device *dev)
+{
+     return of_genpd_sync_state(dev->of_node);
+}
+
  /**
   * of_genpd_add_provider_simple() - Register a simple PM domain provider
   * @np: Device node pointer associated with the PM domain provider.

@@ -2628,6 +2633,8 @@ int of_genpd_add_provider_simple(struct device_node *np,
      if (!dev && !genpd_is_no_sync_state(genpd)) {
              genpd->sync_state = GENPD_SYNC_STATE_SIMPLE;
              device_set_node(&genpd->dev, fwnode);
+     } else {
+             dev_set_drv_sync_state(dev, genpd_sync_state);
      }

      put_device(dev);

@@ -2700,6 +2707,8 @@ int of_genpd_add_provider_onecell(struct device_node *np,
      dev = get_dev_from_fwnode(fwnode);
      if (!dev)
              sync_state = true;
+     else
+             dev_set_drv_sync_state(dev, genpd_sync_state);

      put_device(dev);

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?

Thanks
Jon

[0] https://lore.kernel.org/all/20250701114733.636510-10-ulf.hansson@linaro.org/ (local)
--
nvpublic

Kind regards
Uffe