Re: [PATCH] gpio: event-mon: Use O_RDONLY instead of 0 for open()

[Bartosz Golaszewski]

On Wed, May 20, 2026 at 12:18 PM <2564278112@xxxxxx> wrote:
>
> From: Wang Jiang <jiangwang@xxxxxxxxxx>
>
> Using explicit O_RDONLY flag for open() improves code readability
> and aligns with kernel coding standards instead of using raw 0.
>
> Signed-off-by: Wang Jiang <jiangwang@xxxxxxxxxx>
> ---
>  tools/gpio/gpio-event-mon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c
> index b70813b0bf8e..590ca8db25cf 100644
> --- a/tools/gpio/gpio-event-mon.c
> +++ b/tools/gpio/gpio-event-mon.c
> @@ -41,7 +41,7 @@ int monitor_device(const char *device_name,
>         if (ret < 0)
>                 return -ENOMEM;
>
> -       cfd = open(chrdev_name, 0);
> +       cfd = open(chrdev_name, O_RDONLY);
>         if (cfd == -1) {
>                 ret = -errno;
>                 fprintf(stderr, "Failed to open %s\n", chrdev_name);
> --
> 2.25.1
>
>

Why only here and not elsewhere? Please mention in the commit message
that 0 is effectively O_RDONLY so there's no functional change.

Bart