Received-SPF: pass (google.com: domain of linux-kernel+bounces-213926-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <20240609-acpi-sbs-sysfs-group-v1-1-7f0bf95523e7@weissschuh.net>
In-Reply-To: <20240609-acpi-sbs-sysfs-group-v1-1-7f0bf95523e7@weissschuh.net>
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Thu, 13 Jun 2024 21:31:23 +0200
Message-ID: <CAJZ5v0im2ThDaMyV3bEtYsQYWJH0Y9sYVjpJJ0Zb-wBk_wZr0Q@mail.gmail.com>
Subject: Re: [PATCH] ACPI: SBS: manage alarm sysfs attribute through psy core
To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>, Len Brown <lenb@kernel.org>, linux-acpi@vger.kernel.org, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Sun, Jun 9, 2024 at 1:13=E2=80=AFPM Thomas Wei=C3=9Fschuh <linux@weisssc=
huh.net> wrote:
>
> Let the power supply core register the attribute.
> This ensures that the attribute is created before the device is
> announced to userspace, avoiding a race condition.
>
> Signed-off-by: Thomas Wei=C3=9Fschuh <linux@weissschuh.net>
> ---
> Only compile-tested.
>
> This is the SBS equivalent of
> "ACPI: battery: create alarm sysfs attribute atomically" [0]
>
> [0] https://lore.kernel.org/lkml/20240609-acpi-battery-cleanup-v1-5-34451=
7bdca73@weisss
> ---
>  drivers/acpi/sbs.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
> index dc8164b182dc..442c5905d43b 100644
> --- a/drivers/acpi/sbs.c
> +++ b/drivers/acpi/sbs.c
> @@ -77,7 +77,6 @@ struct acpi_battery {
>         u16 spec;
>         u8 id;
>         u8 present:1;
> -       u8 have_sysfs_alarm:1;
>  };
>
>  #define to_acpi_battery(x) power_supply_get_drvdata(x)
> @@ -462,12 +461,18 @@ static ssize_t acpi_battery_alarm_store(struct devi=
ce *dev,
>         return count;
>  }
>
> -static const struct device_attribute alarm_attr =3D {
> +static struct device_attribute alarm_attr =3D {
>         .attr =3D {.name =3D "alarm", .mode =3D 0644},
>         .show =3D acpi_battery_alarm_show,
>         .store =3D acpi_battery_alarm_store,
>  };
>
> +static struct attribute *acpi_battery_attrs[] =3D {
> +       &alarm_attr.attr,
> +       NULL
> +};
> +ATTRIBUTE_GROUPS(acpi_battery);
> +
>  /* ---------------------------------------------------------------------=
-----
>                                   Driver Interface
>     ---------------------------------------------------------------------=
----- */
> @@ -518,7 +523,10 @@ static int acpi_battery_read(struct acpi_battery *ba=
ttery)
>  static int acpi_battery_add(struct acpi_sbs *sbs, int id)
>  {
>         struct acpi_battery *battery =3D &sbs->battery[id];
> -       struct power_supply_config psy_cfg =3D { .drv_data =3D battery, }=
;
> +       struct power_supply_config psy_cfg =3D {
> +               .drv_data =3D battery,
> +               .attr_grp =3D acpi_battery_groups,
> +       };
>         int result;
>
>         battery->id =3D id;
> @@ -548,10 +556,6 @@ static int acpi_battery_add(struct acpi_sbs *sbs, in=
t id)
>                 goto end;
>         }
>
> -       result =3D device_create_file(&battery->bat->dev, &alarm_attr);
> -       if (result)
> -               goto end;
> -       battery->have_sysfs_alarm =3D 1;
>        end:
>         pr_info("%s [%s]: Battery Slot [%s] (battery %s)\n",
>                ACPI_SBS_DEVICE_NAME, acpi_device_bid(sbs->device),
> @@ -563,11 +567,8 @@ static void acpi_battery_remove(struct acpi_sbs *sbs=
, int id)
>  {
>         struct acpi_battery *battery =3D &sbs->battery[id];
>
> -       if (battery->bat) {
> -               if (battery->have_sysfs_alarm)
> -                       device_remove_file(&battery->bat->dev, &alarm_att=
r);
> +       if (battery->bat)
>                 power_supply_unregister(battery->bat);
> -       }
>  }
>
>  static int acpi_charger_add(struct acpi_sbs *sbs)
>
> ---

Applied as 6.11 material, thanks!