Re: [Resend Patch 9/9] I2C/ACPI: Add CONFIG_I2C_ACPI config

From: Lan Tianyu
Date: Wed Apr 23 2014 - 01:47:45 EST


On 2014å04æ22æ 19:45, Mika Westerberg wrote:
> On Tue, Apr 22, 2014 at 02:24:15PM +0800, Lan Tianyu wrote:
>> This patch is to add CONFIG_I2C_ACPI. Current there is a race between
>> removing I2C ACPI operation region and ACPI AML code accessing.
>> So make i2c core built-in if CONFIG_I2C_ACPI is set.
>>
>> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
>> ---
>> drivers/i2c/Kconfig | 17 ++++++++++++++++-
>> drivers/i2c/Makefile | 2 +-
>> include/linux/i2c.h | 2 +-
>> 3 files changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
>> index 7b7ea32..c670d49 100644
>> --- a/drivers/i2c/Kconfig
>> +++ b/drivers/i2c/Kconfig
>> @@ -2,7 +2,9 @@
>> # I2C subsystem configuration
>> #
>>
>> -menuconfig I2C
>> +menu "I2C support"
>> +
>> +config I2C
>> tristate "I2C support"
>> select RT_MUTEXES
>> ---help---
>> @@ -21,6 +23,17 @@ menuconfig I2C
>> This I2C support can also be built as a module. If so, the module
>> will be called i2c-core.
>>
>> +config I2C_ACPI
>> + bool "I2C ACPI support"
>> + select I2C
>> + depends on ACPI
>> + default y
>> + help
>> + Say Y here if you want to enable I2C ACPI function. ACPI table
>> + provides I2C slave devices' information to enumerate these devices.
>> + This option also allows ACPI AML code to access I2C slave devices
>> + via I2C ACPI operation region to fulfill ACPI method.
>> +
>
> I'm wondering, can we provide some sort of wrapper function from ACPI core
> that is guaranteed to be built in to the kernel image and use it instead of
> adding new Kconfig options?
>
Cc: LV

LV tried to fix the issue via wrapper solution in the ACPI code before.
https://lkml.org/lkml/2013/7/23/87

He has a plan to resolve the issue in ACPICA later.

Other choice is to increase the i2c-core module count to prevent it
being unloaded when i2c operation region handler is installed. Remove
the code When LV finish his job.

--
Best regards
Tianyu Lan
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