Re: [PATCH v7 4/9] acpi/arm64: Add GTDT table parse driver

[Rafael J. Wysocki]

On Wed, Jul 13, 2016 at 11:08 PM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> On Wed, Jul 13, 2016 at 10:30:37PM +0200, Rafael J. Wysocki wrote:
>> On Wed, Jul 13, 2016 at 7:53 PM,  <fu.wei@xxxxxxxxxx> wrote:
>> > From: Fu Wei <fu.wei@xxxxxxxxxx>
>> >
>> > This patch adds support for parsing arch timer in GTDT,
>> > provides some kernel APIs to parse all the PPIs and
>> > always-on info in GTDT and export them.
>> >
>> > By this driver, we can simplify arm_arch_timer drivers, and
>> > separate the ACPI GTDT knowledge from it.
>> >
>> > Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
>> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
>> > ---
>> >  drivers/acpi/Kconfig           |   5 ++
>> >  drivers/acpi/Makefile          |   1 +
>> >  drivers/acpi/arm64/Kconfig     |  15 ++++
>> >  drivers/acpi/arm64/Makefile    |   1 +
>> >  drivers/acpi/arm64/acpi_gtdt.c | 170 +++++++++++++++++++++++++++++++++++++++++
>> >  include/linux/acpi.h           |   6 ++
>> >  6 files changed, 198 insertions(+)
>> >
>> > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>> > index b7e2e77..1cdc7d2 100644
>> > --- a/drivers/acpi/Kconfig
>> > +++ b/drivers/acpi/Kconfig
>> > @@ -521,4 +521,9 @@ config XPOWER_PMIC_OPREGION
>> >
>> >  endif
>> >
>> > +if ARM64
>> > +source "drivers/acpi/arm64/Kconfig"
>> > +
>> > +endif
>> > +
>> >  endif  # ACPI
>> > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> > index 251ce85..1a94ff7 100644
>> > --- a/drivers/acpi/Makefile
>> > +++ b/drivers/acpi/Makefile
>> > @@ -99,5 +99,6 @@ obj-$(CONFIG_ACPI_EXTLOG)     += acpi_extlog.o
>> >  obj-$(CONFIG_PMIC_OPREGION)    += pmic/intel_pmic.o
>> >  obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
>> >  obj-$(CONFIG_XPOWER_PMIC_OPREGION) += pmic/intel_pmic_xpower.o
>> > +obj-$(CONFIG_ARM64)    += arm64/
>> >
>> >  video-objs                     += acpi_video.o video_detect.o
>> > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>> > new file mode 100644
>> > index 0000000..ff5c253
>> > --- /dev/null
>> > +++ b/drivers/acpi/arm64/Kconfig
>> > @@ -0,0 +1,15 @@
>> > +#
>> > +# ACPI Configuration for ARM64
>> > +#
>> > +
>> > +menu "The ARM64-specific ACPI Support"
>> > +
>> > +config ACPI_GTDT
>> > +       bool "ACPI GTDT table Support"
>>
>> This should depend on ARM64.
>>
>> Also I wonder if it needs to be user-selectable?  Wouldn't it be
>> better to enable it by default when building for ARM64 with ACPI?
>>
> It is currently selected in patch 9, in the watchdog driver's Kconfig
> entry.

Well, it still doesn't have to be user-selectable for that. :-)

> Not sure if I like that; maybe the watchdog driver should depend
> on it instead ?

If the watchdog is not the only user of it (and I don't think it is),
it would be better to arrange things this way.

Thanks,
Rafael