linux-kernel - Re: [PATCH v5 03/10] acpi/ac: Move handler installing logic to driver

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Date:   Thu, 29 Jun 2023 17:55:50 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Michal Wilczynski <michal.wilczynski@...el.com>
Cc:     linux-acpi@...r.kernel.org, rafael@...nel.org,
        dan.j.williams@...el.com, vishal.l.verma@...el.com,
        lenb@...nel.org, dave.jiang@...el.com, ira.weiny@...el.com,
        rui.zhang@...el.com, linux-kernel@...r.kernel.org,
        nvdimm@...ts.linux.dev,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Subject: Re: [PATCH v5 03/10] acpi/ac: Move handler installing logic to driver

On Fri, Jun 16, 2023 at 6:51 PM Michal Wilczynski
<michal.wilczynski@...el.com> wrote:
>
> Currently logic for installing notifications from ACPI devices is
> implemented using notify callback in struct acpi_driver. Preparations
> are being made to replace acpi_driver with more generic struct
> platform_driver, which doesn't contain notify callback. Furthermore
> as of now handlers are being called indirectly through
> acpi_notify_device(), which decreases performance.
>
> Call acpi_dev_install_notify_handler() at the end of .add() callback.
> Call acpi_dev_remove_notify_handler() at the beginning of .remove()
> callback. Change arguments passed to the notify function to match with
> what's required by acpi_install_notify_handler(). Remove .notify
> callback initialization in acpi_driver.
>
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Signed-off-by: Michal Wilczynski <michal.wilczynski@...el.com>
> ---
>  drivers/acpi/ac.c | 33 ++++++++++++++++++++++++---------
>  1 file changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
> index 1ace70b831cd..207ee3c85bad 100644
> --- a/drivers/acpi/ac.c
> +++ b/drivers/acpi/ac.c
> @@ -34,7 +34,7 @@ MODULE_LICENSE("GPL");
>
>  static int acpi_ac_add(struct acpi_device *device);
>  static void acpi_ac_remove(struct acpi_device *device);
> -static void acpi_ac_notify(struct acpi_device *device, u32 event);
> +static void acpi_ac_notify(acpi_handle handle, u32 event, void *data);
>
>  static const struct acpi_device_id ac_device_ids[] = {
>         {"ACPI0003", 0},
> @@ -54,11 +54,9 @@ static struct acpi_driver acpi_ac_driver = {
>         .name = "ac",
>         .class = ACPI_AC_CLASS,
>         .ids = ac_device_ids,
> -       .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
>         .ops = {
>                 .add = acpi_ac_add,
>                 .remove = acpi_ac_remove,
> -               .notify = acpi_ac_notify,
>                 },
>         .drv.pm = &acpi_ac_pm,
>  };
> @@ -128,9 +126,12 @@ static enum power_supply_property ac_props[] = {
>  };
>
>  /* Driver Model */
> -static void acpi_ac_notify(struct acpi_device *device, u32 event)
> +static void acpi_ac_notify(acpi_handle handle, u32 event, void *data)
>  {
> -       struct acpi_ac *ac = acpi_driver_data(device);

This line doesn't need to be changed.  Just add the device variable
definition above it.

And the same pattern is present in the other patches in the series.

> +       struct acpi_device *device = data;
> +       struct acpi_ac *ac;
> +
> +       ac = acpi_driver_data(device);
>
>         if (!ac)
>                 return;