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

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Date:   Fri, 30 Jun 2023 11:39:22 +0200
From:   "Wilczynski, Michal" <michal.wilczynski@...el.com>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
CC:     <linux-acpi@...r.kernel.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 6/29/2023 5:55 PM, Rafael J. Wysocki wrote:
> 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.

I like the Reverse Christmas Tree, but sure will change that

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