Re: [PATCH v8 12/21] v4l: async: Introduce helpers for calling async ops callbacks

[Hans Verkuil]

On 09/05/2017 03:05 PM, Sakari Ailus wrote:
> Add three helper functions to call async operations callbacks. Besides
> simplifying callbacks, this allows async notifiers to have no ops set,
> i.e. it can be left NULL.

What is the use-case of that?

Anyway:

Acked-by: Hans Verkuil <hans.verk...@cisco.com>

Regards,

        Hans

> 
> Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
> ---
>  drivers/media/v4l2-core/v4l2-async.c | 49 
> ++++++++++++++++++++++++++----------
>  include/media/v4l2-async.h           |  1 +
>  2 files changed, 37 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c 
> b/drivers/media/v4l2-core/v4l2-async.c
> index f7eb3713207a..baee95eacbba 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -25,6 +25,34 @@
>  #include <media/v4l2-fwnode.h>
>  #include <media/v4l2-subdev.h>
>  
> +static int v4l2_async_notifier_call_bound(struct v4l2_async_notifier *n,
> +                                       struct v4l2_subdev *subdev,
> +                                       struct v4l2_async_subdev *asd)
> +{
> +     if (!n->ops || !n->ops->bound)
> +             return 0;
> +
> +     return n->ops->bound(n, subdev, asd);
> +}
> +
> +static void v4l2_async_notifier_call_unbind(struct v4l2_async_notifier *n,
> +                                         struct v4l2_subdev *subdev,
> +                                         struct v4l2_async_subdev *asd)
> +{
> +     if (!n->ops || !n->ops->unbind)
> +             return;
> +
> +     n->ops->unbind(n, subdev, asd);
> +}
> +
> +static int v4l2_async_notifier_call_complete(struct v4l2_async_notifier *n)
> +{
> +     if (!n->ops || !n->ops->complete)
> +             return 0;
> +
> +     return n->ops->complete(n);
> +}
> +
>  static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
>  {
>  #if IS_ENABLED(CONFIG_I2C)
> @@ -107,16 +135,13 @@ static int v4l2_async_match_notify(struct 
> v4l2_async_notifier *notifier,
>  {
>       int ret;
>  
> -     if (notifier->ops->bound) {
> -             ret = notifier->ops->bound(notifier, sd, asd);
> -             if (ret < 0)
> -                     return ret;
> -     }
> +     ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
> +     if (ret < 0)
> +             return ret;
>  
>       ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
>       if (ret < 0) {
> -             if (notifier->ops->unbind)
> -                     notifier->ops->unbind(notifier, sd, asd);
> +             v4l2_async_notifier_call_unbind(notifier, sd, asd);
>               return ret;
>       }
>  
> @@ -128,8 +153,8 @@ static int v4l2_async_match_notify(struct 
> v4l2_async_notifier *notifier,
>       /* Move from the global subdevice list to notifier's done */
>       list_move(&sd->async_list, &notifier->done);
>  
> -     if (list_empty(&notifier->waiting) && notifier->ops->complete)
> -             return notifier->ops->complete(notifier);
> +     if (list_empty(&notifier->waiting))
> +             return v4l2_async_notifier_call_complete(notifier);
>  
>       return 0;
>  }
> @@ -215,8 +240,7 @@ void v4l2_async_notifier_unregister(struct 
> v4l2_async_notifier *notifier)
>       list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
>               v4l2_async_cleanup(sd);
>  
> -             if (notifier->ops->unbind)
> -                     notifier->ops->unbind(notifier, sd, sd->asd);
> +             v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
>       }
>  
>       mutex_unlock(&list_lock);
> @@ -294,8 +318,7 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
>  
>       v4l2_async_cleanup(sd);
>  
> -     if (notifier->ops->unbind)
> -             notifier->ops->unbind(notifier, sd, sd->asd);
> +     v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
>  
>       mutex_unlock(&list_lock);
>  }
> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> index 3c48f8b66d12..3bc8a7c0d83f 100644
> --- a/include/media/v4l2-async.h
> +++ b/include/media/v4l2-async.h
> @@ -164,4 +164,5 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd);
>   * @sd: pointer to &struct v4l2_subdev
>   */
>  void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
> +
>  #endif
>