Re: [PATCH 3/4] thermal/core: Allocate the thermal class dynamically

[Rafael J. Wysocki]

On Fri, May 8, 2026 at 8:05 PM Daniel Lezcano
<daniel.lezcano@xxxxxxxxxxxxxxxx> wrote:
>
> Use class_create() instead of a statically allocated struct class.
>
> This allows the thermal class to be managed through a dynamically
> allocated class object and avoids keeping a static class instance
> around.

I changed it the other way around during the last cycle, so is it
really worth changing again?

> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxxxxxxxx>
> ---
>  drivers/thermal/thermal_core.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index a79fc4cdb078..748ab76823a3 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -949,9 +949,7 @@ static void thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
>         kfree(pos);
>  }
>
> -static const struct class thermal_class = {
> -       .name = "thermal",
> -};
> +static struct class *thermal_class;
>  static bool thermal_class_unavailable __ro_after_init = true;
>
>  static inline
> @@ -1078,7 +1076,7 @@ __thermal_cooling_device_register(struct device_node *np,
>         cdev->np = np;
>         cdev->ops = ops;
>         cdev->updated = false;
> -       cdev->device.class = &thermal_class;
> +       cdev->device.class = thermal_class;
>         cdev->device.release = thermal_cdev_release;
>         cdev->devdata = devdata;
>
> @@ -1574,7 +1572,7 @@ thermal_zone_device_register_with_trips(const char *type,
>         if (!tz->ops.critical)
>                 tz->ops.critical = thermal_zone_device_critical;
>
> -       tz->device.class = &thermal_class;
> +       tz->device.class = thermal_class;
>         tz->device.release = thermal_zone_device_release;
>         tz->devdata = devdata;
>         tz->num_trips = num_trips;
> @@ -1898,15 +1896,18 @@ static int __init thermal_init(void)
>         if (result)
>                 goto destroy_workqueue;
>
> -       result = class_register(&thermal_class);
> -       if (result)
> +       thermal_class = class_create("thermal");
> +       if (IS_ERR(thermal_class)) {
> +               result = PTR_ERR(thermal_class);
>                 goto unregister_governors;
> +       }
>
>         thermal_class_unavailable = false;
>
>         return 0;
>
>  unregister_governors:
> +       thermal_class = NULL;
>         thermal_unregister_governors();
>  destroy_workqueue:
>         destroy_workqueue(thermal_wq);
> --
> 2.43.0
>
>