Re: [PATCH v2 -next] video: backlight: use DEFINE_MUTEX() for mutex lock

[Daniel Thompson <daniel.thompson@linaro.org>]

On Thu, Dec 24, 2020 at 09:26:01PM +0800, Zheng Yongjun wrote:
> mutex lock can be initialized automatically with DEFINE_MUTEX()
> rather than explicitly calling mutex_init().
> 
> Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
> ---
>  drivers/video/backlight/backlight.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> index 537fe1b376ad..d7a09c422547 100644
> --- a/drivers/video/backlight/backlight.c
> +++ b/drivers/video/backlight/backlight.c
> @@ -64,7 +64,7 @@
>   */
>  
>  static struct list_head backlight_dev_list;
> -static struct mutex backlight_dev_list_mutex;
> +static DEFINE_MUTEX(backlight_dev_list_mutex);
>  static struct blocking_notifier_head backlight_notifier;

Why do we want to convert one of these variables to use a
static initializers but leave the other two unchanged? Surely they
should all be changed.


Daniel.


>  
>  static const char *const backlight_types[] = {
> @@ -757,7 +757,6 @@ static int __init backlight_class_init(void)
>  	backlight_class->dev_groups = bl_device_groups;
>  	backlight_class->pm = &backlight_class_dev_pm_ops;
>  	INIT_LIST_HEAD(&backlight_dev_list);
> -	mutex_init(&backlight_dev_list_mutex);
>  	BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier);
>  
>  	return 0;
> -- 
> 2.22.0
>