On 2014?07?08? 05:13, Rafael J. Wysocki wrote:

On Wednesday, July 02, 2014 04:47:25 PM Hanjun Guo wrote:

quoted

The use of _PDC is deprecated in ACPI 3.0 in favor of _OSC,
as ARM platform is supported only in ACPI 5.0 or higher version,
_PDC will not be used in ARM platform, so make Make _PDC only for
platforms with Intel CPUs.

Introduce ARCH_HAS_ACPI_PDC and move _PDC related code in ACPI
processor driver into a single file processor_pdc.c, make x86
and ia64 select ARCH_HAS_ACPI_PDC when ACPI is enabled.

This patch also use pr_* to replace printk to fix the checkpatch
warning and factor acpi_processor_alloc_pdc() a little bit to
avoid duplicate pr_err() code.

Suggested-by: Robert Richter <rric@kernel.org>
Signed-off-by: Hanjun Guo <redacted>
---
 arch/ia64/Kconfig             |    1 +
 arch/x86/Kconfig              |    1 +
 drivers/acpi/Kconfig          |   10 ++
 drivers/acpi/Makefile         |    1 +
 drivers/acpi/internal.h       |    5 +
 drivers/acpi/processor_core.c |  198 ---------------------------------------
 drivers/acpi/processor_pdc.c  |  206 +++++++++++++++++++++++++++++++++++++++++
 7 files changed, 224 insertions(+), 198 deletions(-)
 create mode 100644 drivers/acpi/processor_pdc.c

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index f82b352..cde2626 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig

@@ -10,6 +10,7 @@ config IA64
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select PCI if (!IA64_HP_SIM)
 	select ACPI if (!IA64_HP_SIM)
+	select ARCH_HAS_ACPI_PDC if ACPI

The ARCH_HAS part doesn't seem to be particularly consistent with
the existing naming.  ARCH_MIGHT_HAVE_ACPI_PDC would be better IMO.

OK, I will update the patch.

quoted

 	select PM if (!IA64_HP_SIM)
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4865d44..d60cec7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig

@@ -21,6 +21,7 @@ config X86_64
 ### Arch settings
 config X86
 	def_bool y
+	select ARCH_HAS_ACPI_PDC if ACPI
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 70eaf7a..0e6f72d 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig

@@ -367,6 +367,16 @@ config ACPI_REDUCED_HARDWARE_ONLY
 
 	If you are unsure what to do, do not enable this option.
 
+config ARCH_HAS_ACPI_PDC
+	bool
+	help
+	  The _PDC object provides OSPM a mechanism to convey to the platform
+	  the capabilities supported by OSPM for processor power management.
+	  This allows the platform to modify the ACPI namespace objects returning
+	  configuration information for processor power management based on the
+	  level of support provided by OSPM.The use of _PDC is deprecated in
+	  ACPI 3.0 in favor of _OSC.

Is the help actually useful?  This doesn't seem to be user-selectable, does it?

Yes, my bad, I will remove the help in next version.

Thanks
Hanjun