linux-kernel - Re: [PATCH v5 09/10] acpi/nfit: Move handler installing logic to driver

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Message-ID: <d4ebf8ba-6f95-d20c-d7fb-e97b6535f71f@intel.com>
Date:   Fri, 30 Jun 2023 11:55:01 +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 09/10] acpi/nfit: Move handler installing logic to
 driver



On 6/29/2023 6:18 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/nfit/core.c | 24 ++++++++++++++++++------
>>  1 file changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
>> index 95930e9d776c..a281bdfee8a0 100644
>> --- a/drivers/acpi/nfit/core.c
>> +++ b/drivers/acpi/nfit/core.c
>> @@ -3312,11 +3312,13 @@ void acpi_nfit_shutdown(void *data)
>>  }
>>  EXPORT_SYMBOL_GPL(acpi_nfit_shutdown);
>>
>> -static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
>> +static void acpi_nfit_notify(acpi_handle handle, u32 event, void *data)
>>  {
>> -       device_lock(&adev->dev);
>> -       __acpi_nfit_notify(&adev->dev, adev->handle, event);
>> -       device_unlock(&adev->dev);
> It's totally not necessary to rename the ACPI device variable here.
>
> Just add
>
> struct acpi_device *adev = data;
>
> to this function.

Sure, is adev a preferred name for acpi_device ? I've seen a mix of different naming
in drivers, some use device, adev, acpi_dev and so on. I suppose it's not a big deal, but
it would be good to know.

>
>> +       struct acpi_device *device = data;
>> +
>> +       device_lock(&device->dev);
>> +       __acpi_nfit_notify(&device->dev, handle, event);
>> +       device_unlock(&device->dev);
>>  }
>>
>>  static int acpi_nfit_add(struct acpi_device *adev)
>> @@ -3375,12 +3377,23 @@ static int acpi_nfit_add(struct acpi_device *adev)
>>
>>         if (rc)
>>                 return rc;
>> -       return devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc);
>> +
>> +       rc = devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc);
>> +       if (rc)
>> +               return rc;
>> +
>> +       return acpi_dev_install_notify_handler(adev,
>> +                                              ACPI_DEVICE_NOTIFY,
>> +                                              acpi_nfit_notify);
>>  }
>>
>>  static void acpi_nfit_remove(struct acpi_device *adev)
>>  {
>>         /* see acpi_nfit_unregister */
>> +
>> +       acpi_dev_remove_notify_handler(adev,
>> +                                      ACPI_DEVICE_NOTIFY,
>> +                                      acpi_nfit_notify);
>>  }
>>
>>  static void acpi_nfit_update_notify(struct device *dev, acpi_handle handle)
>> @@ -3465,7 +3478,6 @@ static struct acpi_driver acpi_nfit_driver = {
>>         .ops = {
>>                 .add = acpi_nfit_add,
>>                 .remove = acpi_nfit_remove,
>> -               .notify = acpi_nfit_notify,
>>         },
>>  };
>>
>> --