linux-kernel - Re: [PATCH v1] ACPI: battery: Reduce unnecessary calls to acpi_battery

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJZ5v0guh4MGJpaCoh3Guc8BL_37=KHWW10wvK+iD6jZLvZWwg@mail.gmail.com>
Date: Fri, 9 May 2025 20:23:16 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: zhangzihuan <zhangzihuan@...inos.cn>
Cc: rafael@...nel.org, lenb@...nel.org, linux-acpi@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] ACPI: battery: Reduce unnecessary calls to acpi_battery_update()

On Tue, Apr 22, 2025 at 11:11 AM zhangzihuan <zhangzihuan@...inos.cn> wrote:
>
> When entering the acpi_mattery_notify function, no matter what the event
> is, acpi_mattery_update will definitely be called.

I think you mean acpi_battery_update().

> Use the acpi_listen command to listen, sometimes the log looks like this:
>
> battery xxx:00 00000081 00000001
> battery xxx:00 00000000 00000001
> battery xxx:00 00000080 00000001
>
> Firmware manufacturers will customize some events like 0x0, so
> non-matching events will be ignored.

I don't quite get what you are trying to achieve here.

> Signed-off-by: zhangzihuan <zhangzihuan@...inos.cn>
> ---
>  drivers/acpi/battery.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index 6760330a8af5..9446c57b77e7 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -1083,7 +1083,8 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
>                 msleep(battery_notification_delay_ms);
>         if (event == ACPI_BATTERY_NOTIFY_INFO)
>                 acpi_battery_refresh(battery);
> -       acpi_battery_update(battery, false);
> +       if (event == ACPI_BATTERY_NOTIFY_STATUS)
> +               acpi_battery_update(battery, false);

So only call acpi_battery_update() for ACPI_BATTERY_NOTIFY_STATUS.

Why do you think this is the only case in which acpi_battery_update()
needs to be called?

>         acpi_bus_generate_netlink_event(device->pnp.device_class,
>                                         dev_name(&device->dev), event,
>                                         acpi_battery_present(battery));
> --