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From:   Chuhong Yuan <hslester96@gmail.com>
Date:   Sat, 3 Aug 2019 00:16:06 +0800
Message-ID: <CANhBUQ3L29NzKEdpK5MvUZh7E97Co_vHRzjH2KaXxx+93_9WWg@mail.gmail.com>
Subject: Re: [PATCH] niu: Use refcount_t for refcount
Cc:     "David S . Miller" <davem@davemloft.net>,
        Netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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Chuhong Yuan <hslester96@gmail.com> =E4=BA=8E2019=E5=B9=B48=E6=9C=882=E6=97=
=A5=E5=91=A8=E4=BA=94 =E4=B8=8B=E5=8D=888:57=E5=86=99=E9=81=93=EF=BC=9A
>
> refcount_t is better for reference counters since its
> implementation can prevent overflows.
> So convert atomic_t ref counters to refcount_t.
>
> Also convert refcount from 0-based to 1-based.

It seems that directly converting refcount from 0-based to
1-based is infeasible.
I am sorry for this mistake.

Regards,
Chuhong

>
> Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
> ---
>  drivers/net/ethernet/sun/niu.c | 6 +++---
>  drivers/net/ethernet/sun/niu.h | 2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/ni=
u.c
> index 0bc5863bffeb..5bf096e51db7 100644
> --- a/drivers/net/ethernet/sun/niu.c
> +++ b/drivers/net/ethernet/sun/niu.c
> @@ -9464,7 +9464,7 @@ static struct niu_parent *niu_new_parent(struct niu=
 *np,
>         memcpy(&p->id, id, sizeof(*id));
>         p->plat_type =3D ptype;
>         INIT_LIST_HEAD(&p->list);
> -       atomic_set(&p->refcnt, 0);
> +       refcount_set(&p->refcnt, 1);
>         list_add(&p->list, &niu_parent_list);
>         spin_lock_init(&p->lock);
>
> @@ -9524,7 +9524,7 @@ static struct niu_parent *niu_get_parent(struct niu=
 *np,
>                                         port_name);
>                 if (!err) {
>                         p->ports[port] =3D np;
> -                       atomic_inc(&p->refcnt);
> +                       refcount_inc(&p->refcnt);
>                 }
>         }
>         mutex_unlock(&niu_parent_lock);
> @@ -9552,7 +9552,7 @@ static void niu_put_parent(struct niu *np)
>         p->ports[port] =3D NULL;
>         np->parent =3D NULL;
>
> -       if (atomic_dec_and_test(&p->refcnt)) {
> +       if (refcount_dec_and_test(&p->refcnt)) {
>                 list_del(&p->list);
>                 platform_device_unregister(p->plat_dev);
>         }
> diff --git a/drivers/net/ethernet/sun/niu.h b/drivers/net/ethernet/sun/ni=
u.h
> index 04c215f91fc0..755e6dd4c903 100644
> --- a/drivers/net/ethernet/sun/niu.h
> +++ b/drivers/net/ethernet/sun/niu.h
> @@ -3071,7 +3071,7 @@ struct niu_parent {
>
>         struct niu              *ports[NIU_MAX_PORTS];
>
> -       atomic_t                refcnt;
> +       refcount_t              refcnt;
>         struct list_head        list;
>
>         spinlock_t              lock;
> --
> 2.20.1
>