Re: [PATCH v4 2/2] mfd: axp20x-i2c: Document that this must be builtin on x86

From: Lee Jones
Date: Mon May 22 2017 - 06:56:12 EST


On Mon, 15 May 2017, Hans de Goede wrote:

> On x86 the axp288 PMIC provides an ACPI OpRegion handler, which must be
> available before other drivers using it are loaded, which can only be
> ensured if the mfd, OpRegionr and i2c-bus drivers are built in.
>
> Since the axp20x mfd code is used on non X86 too we cannot simply change
> this into a bool, I've tried some Kconfig magic with if x86 but I could
> not get this working correctly, so this commit just documents that this
> should be builtin on x86, which fixes errors like these during boot:
>
> mmc0: SDHCI controller on ACPI [80860F14:00] using ADMA
> ACPI Error: No handler for Region [REGS] (ffff93543b0cc3a8) [UserDefinedRegion]
> ACPI Error: Region UserDefinedRegion (ID=143) has no handler (20170119/exfldio-2
> ACPI Error: Method parse/execution failed [\_SB.PCI0.I2C7.PMI5.GET] (Node ffff93
> ACPI Error: Method parse/execution failed [\_SB.PCI0.SHC1._PS0] (Node ffff93543b
> acpi 80860F14:02: Failed to change power state to D0
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>

Would be good to get an Ack by the users/maintainers of this driver.

> ---
> Changes in v2:
> -Fix Kconfig depends and selects to fix warning reported by kbuild test robot
> -Improve commit msg (add example of ACPI errors this avoids)
> Changes in v3:
> -Since the axp20x mfd code is used on ARM too where it does not necessarily
> need to be builtin settle for simply documenting the need to have this
> builtin on x86
> ---
> drivers/mfd/Kconfig | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 61ebda81e134..cfac1e8a0a20 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -160,6 +160,11 @@ config MFD_AXP20X_I2C
> components like regulators or the PEK (Power Enable Key) under the
> corresponding menus.
>
> + Note on x86 this provides an ACPI OpRegion, so this must be 'y'
> + (builtin) and not a module, as the OpRegion must be available as
> + soon as possible. For the same reason the i2c bus driver options

Nit: s/i2c/I2C/

> + I2C_DESIGNWARE_PLATFORM and I2C_DESIGNWARE_BAYTRAIL must be 'y' too.
> +
> config MFD_AXP20X_RSB
> tristate "X-Powers AXP series PMICs with RSB"
> select MFD_AXP20X

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog