Re: [PATCH v3 -next] staging: vc04_services: use DEFINE_MUTEX() for mutex lock

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jan 05, 2021 at 10:05:47AM +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>
> ---
>  .../vc04_services/interface/vchiq_arm/vchiq_connected.c     | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
> index 79b75efa6868..938307f39b9c 100644
> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_connected.c
> @@ -12,15 +12,13 @@ static   int                        g_connected;
>  static   int                        g_num_deferred_callbacks;
>  static   VCHIQ_CONNECTED_CALLBACK_T g_deferred_callback[MAX_CALLBACKS];
>  static   int                        g_once_init;
> -static   struct mutex               g_connected_mutex;
> +static   DEFINE_MUTEX(g_connected_mutex);
>  
>  /* Function to initialize our lock */
>  static void connected_init(void)
>  {
> -	if (!g_once_init) {
> -		mutex_init(&g_connected_mutex);
> +	if (!g_once_init)
>  		g_once_init = 1;
> -	}

Why do you still need g_once_init now?