Re: [PATCH v5 07/11] platform/x86: int3472: Split into 2 drivers

[Hans de Goede]

Hi,

On 11/2/21 15:16, Andy Shevchenko wrote:
> On Tue, Nov 2, 2021 at 11:49 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>>
>> The intel_skl_int3472.ko module contains 2 separate drivers,
>> the int3472_discrete platform driver and the int3472_tps68470
>> I2C-driver.
>>
>> These 2 drivers contain very little shared code, only
>> skl_int3472_get_acpi_buffer() and skl_int3472_fill_cldb() are
>> shared.
>>
>> Split the module into 2 drivers, linking the little shared code
>> directly into both.
>>
>> This will allow us to add soft-module dependencies for the
>> tps68470 clk, gpio and regulator drivers to the new
>> intel_skl_int3472_tps68470.ko to help with probe ordering issues
>> without causing these modules to get loaded on boards which only
>> use the int3472_discrete platform driver.
>>
>> While at it also rename the .c and .h files to remove the
>> cumbersome intel_skl_int3472_ prefix.
> 
> ...
> 
>> +union acpi_object *skl_int3472_get_acpi_buffer(struct acpi_device *adev, char *id)
>> +{
>> +       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
>> +       acpi_handle handle = adev->handle;
>> +       union acpi_object *obj;
>> +       acpi_status status;
>> +
>> +       status = acpi_evaluate_object(handle, id, NULL, &buffer);
>> +       if (ACPI_FAILURE(status))
>> +               return ERR_PTR(-ENODEV);
>> +
>> +       obj = buffer.pointer;
>> +       if (!obj)
>> +               return ERR_PTR(-ENODEV);
>> +
>> +       if (obj->type != ACPI_TYPE_BUFFER) {
>> +               acpi_handle_err(handle, "%s object is not an ACPI buffer\n", id);
> 
>> +               kfree(obj);
> 
> I'm wondering if we should use more of the ACPI_FREE() calls as
> opposed to ACPI_ALLOCATE_BUFFER. Ditto for all such cases.

Basically the situation surrounding this is a mess, most code seems to
simply use plain kfree() which I find much more readable, but some
code indeed is using ACPI_FREE(), which I believe is really mostly
meant for internal use by the acpica code.

Eitherway until one of the ACPI maintainers clearly states
that we really should use ACPI_FREE() here I plan to stick with kfree()
because:

1. I find it much more readable.
2. AFAICT ACPI_FREE() is meant for acpica internal use
   (basically it is part of the OS abstraction bits of acpica)

Regards,

Hans