Re: [RESEND PATCH v3 07/32] media: v4l: async: Drop unneeded list entry initialisation

[Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>]

Hi Sakari,

Thank you for the patch.

On Thu, May 25, 2023 at 12:15:50PM +0300, Sakari Ailus wrote:
> The list entry is initialised as a head in v4l2_async_register_subdev()
> just before being added to the list. This isn't needed, drop the
> initialisation.

Is this really unneeded ? Before the initialization and the list_add()
call there are a few code paths that can access the async_list. For
instance, the error path calls v4l2_async_cleanup(), which calls

	list_del_init(&sd->async_list);

That won't work well on an uninitialized (or zero-initialized)
list_head.

> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
>  drivers/media/v4l2-core/v4l2-async.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 320fe5cbaaf41..aef9a16e892ef 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -823,8 +823,6 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>  
>  	mutex_lock(&list_lock);
>  
> -	INIT_LIST_HEAD(&sd->async_list);
> -
>  	list_for_each_entry(notifier, &notifier_list, list) {
>  		struct v4l2_device *v4l2_dev =
>  			v4l2_async_nf_find_v4l2_dev(notifier);

-- 
Regards,

Laurent Pinchart