Hi, Tianyu > From: Lan, Tianyu > Sent: Wednesday, April 23, 2014 1:40 PM > > On 2014年04月22日 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. You may see it implemented in ACPICA after several release. If you need a fix for now, you can use the patch pointed to by the link you've provided, Or you could find an updated one here: acpi-ipmi13.patch archived in (https://bugzilla.kernel.org/attachment.cgi?id=112611) I think the solution you've provided in this patch is also reasonable for now. IPMI also uses a similar solution to solve this issue. Please refer to the CONFIG_ACPI_IPMI. The story can be found at: http://www.spinics.net/lists/linux-acpi/msg49044.html And the similar solution can be found at: http://www.spinics.net/lists/linux-acpi/msg49184.html Thanks and best regards -Lv > > -- > Best regards > Tianyu Lan ��.n��������+%������w��{.n�����{��-��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
