Re: [PATCH v7 1/3] PM / wakeup: Drop wakeup_source_init(), wakeup_source_prepare()

[Stephen Boyd <swboyd@chromium.org>]

Quoting Tri Vo (2019-08-05 10:58:46)
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index ee31d4f8d856..3938892c8903 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -72,23 +72,6 @@ static struct wakeup_source deleted_ws = {
>         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
>  };
>  
> -/**
> - * wakeup_source_prepare - Prepare a new wakeup source for initialization.
> - * @ws: Wakeup source to prepare.
> - * @name: Pointer to the name of the new wakeup source.
> - *
> - * Callers must ensure that the @name string won't be freed when @ws is still in
> - * use.
> - */
> -void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
> -{
> -       if (ws) {
> -               memset(ws, 0, sizeof(*ws));
> -               ws->name = name;
> -       }
> -}
> -EXPORT_SYMBOL_GPL(wakeup_source_prepare);
> -
>  /**
>   * wakeup_source_create - Create a struct wakeup_source object.
>   * @name: Name of the new wakeup source.
> @@ -96,13 +79,23 @@ EXPORT_SYMBOL_GPL(wakeup_source_prepare);
>  struct wakeup_source *wakeup_source_create(const char *name)
>  {
>         struct wakeup_source *ws;
> +       const char *ws_name;
>  
> -       ws = kmalloc(sizeof(*ws), GFP_KERNEL);
> +       ws = kzalloc(sizeof(*ws), GFP_KERNEL);
>         if (!ws)
> -               return NULL;
> +               goto err_ws;
> +
> +       ws_name = kstrdup_const(name, GFP_KERNEL);
> +       if (!ws_name)

Does this intentionally change this function to return an error if
'name' is NULL? Before, wakeup_source_prepare() would just assign
ws->name to NULL, but now it errors out. I don't see how it's good or
useful to allow NULL for the wakeup source name, but it is what it is.

> +               goto err_name;
> +       ws->name = ws_name;
>  
> -       wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
>         return ws;
> +
> +err_name:
> +       kfree(ws);
> +err_ws:
> +       return NULL;
>  }
>  EXPORT_SYMBOL_GPL(wakeup_source_create);
>