Re: [PATCH 1/2] thermal/core: Make the userspace governor deprecated

[Rafael J. Wysocki]

On Tue, Oct 19, 2021 at 3:22 PM Daniel Lezcano
<daniel.lezcano@xxxxxxxxxx> wrote:
>
> The userspace governor is sending temperature when polling is active
> and trip point crossed events. Nothing else.
>
> AFAICT, this governor is used with custom kernels making the userspace
> governor co-existing with another governor on the same thermal zone
> because there was no notification mechanism.
>
> The new netlink thermal notification is able to provide more
> information than the userspace governor and give the opportunity to
> the users of this governor to replace it by a dedicated notification
> framework.
>
> The userspace governor will be removed as its usage is no longer
> needed.
>
> Add a warning message to tell the userspace governor is deprecated.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> ---
>  drivers/thermal/gov_user_space.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/drivers/thermal/gov_user_space.c b/drivers/thermal/gov_user_space.c
> index 82a7198bbe71..95d6d3d6b8f7 100644
> --- a/drivers/thermal/gov_user_space.c
> +++ b/drivers/thermal/gov_user_space.c
> @@ -15,6 +15,14 @@
>
>  #include "thermal_core.h"
>
> +static int user_space_bind(struct thermal_zone_device *tz)
> +{
> +       WARN(1, "Userspace governor deprecated: use thermal netlink "   \
> +            "notification instead\n");

This is really aggressive, because this becomes BUG() in certain
kernel configurations.

pr_warn() should be sufficient IMO.

> +
> +       return 0;
> +}
> +
>  /**
>   * notify_user_space - Notifies user space about thermal events
>   * @tz: thermal_zone_device
> @@ -43,5 +51,6 @@ static int notify_user_space(struct thermal_zone_device *tz, int trip)
>  static struct thermal_governor thermal_gov_user_space = {
>         .name           = "user_space",
>         .throttle       = notify_user_space,
> +       .bind_to_tz     = user_space_bind,
>  };
>  THERMAL_GOVERNOR_DECLARE(thermal_gov_user_space);
> --