pmdomain: core: Prevent registering devices before the bus

We must not register a consumer device to the genpd bus, before registering
the bus itself. Even if this doesn't seem to be an issue, let's add a
simple check to make sure we really avoid this from happening.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250701114733.636510-5-ulf.hansson@linaro.org

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 9a66b728fbbf4a1bee80678742a9c6d152fca73c..93d71164fc560a684607415e311b605ffd21142d 100644 (file)
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -2491,6 +2491,8 @@ struct of_genpd_provider {
 static LIST_HEAD(of_genpd_providers);
 /* Mutex to protect the list above. */
 static DEFINE_MUTEX(of_genpd_mutex);
+/* Used to prevent registering devices before the bus. */
+static bool genpd_bus_registered;
 
 /**
  * genpd_xlate_simple() - Xlate function for direct node-domain mapping
@@ -3179,6 +3181,9 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev,
        if (num_domains < 0 || index >= num_domains)
                return NULL;
 
+       if (!genpd_bus_registered)
+               return ERR_PTR(-ENODEV);
+
        /* Allocate and register device on the genpd bus. */
        virt_dev = kzalloc(sizeof(*virt_dev), GFP_KERNEL);
        if (!virt_dev)
@@ -3357,7 +3362,14 @@ EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
 
 static int __init genpd_bus_init(void)
 {
-       return bus_register(&genpd_bus_type);
+       int ret;
+
+       ret = bus_register(&genpd_bus_type);
+       if (ret)
+               return ret;
+
+       genpd_bus_registered = true;
+       return 0;
 }
 core_initcall(genpd_bus_init);