Re: [PATCH v2] i2c: Allow ACPI_I2C_OPREGION if I2C is built as a module

From: Andy Shevchenko
Date: Wed Jan 24 2018 - 09:46:17 EST


On Wed, Jan 24, 2018 at 8:27 AM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> On Wed, Jan 24, 2018 at 06:56:16AM +0100, Wolfram Sang wrote:
>> On Wed, Jan 03, 2018 at 03:02:31PM +0100, Eric Auger wrote:
>> > If I2C is built as a module, ACPI_I2C_OPREGION cannot be set
>> > and any ACPI opregion calls targeting I2C fail with no opregion found.
>> >
>> > This patch allows ACPI_I2C_OPREGION to be enabled both if I2C is
>> > built into the kernel or built as a module.
>> >
>> > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>>
>> I recall that we had some discussion until ending up with the current
>> solution. And I finally found it again:
>>
>> http://www.serverphorums.com/read.php?12,1001402
>>
>> In any case, I surely want Mika's ack on any change to ACPI related
>> Kconfig symbols. Adding him to CC...
>
> So the problem is/was that what happens if you are in a middle of BIOS
> AML code touching the opregion and someone unloads the opregion handler?
> If you can quarantee nothing bad happens, then I'm fine with the patch :)

I don't think anyone can guarantee this.

I would be fine with patch if and only if it has been tested on
problematic hardware, such as Intel CherryTrail based tablets /
laptops.

--
With Best Regards,
Andy Shevchenko