On Monday, November 18, 2013 09:21:30 PM Hanjun Guo wrote: > On 18 November 2013 21:24, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > > On Monday, November 18, 2013 08:48:05 PM Hanjun Guo wrote: > > > On 18 November 2013 06:29, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > > > > > > On Saturday, November 09, 2013 06:36:11 PM al.stone@xxxxxxxxxx wrote: > > > > > From: Al Stone <ahs3@xxxxxxxxxx> > > > > > > > > > > To enable the hardware reduced mode of ACPI on some platforms (such > > as > > > > > ARM), we need to modify the kernel code and set ACPI_REDUCED_HARDWARE > > > > > to TRUE in the ACPICA source. > > > > > > > > > > This can be done more resonably by introducing a kernel config item > > > > > to enable/disable ACPI_REDUCED_HARDWARE. We can then change the > > kernel > > > > > config instead of having to modify the kernel source directly to > > enable > > > > > the reduced hardware mode of ACPI. > > > > > > > > > > Lv Zheng suggested that this configuration item does not belong in > > > > ACPICA, > > > > > the upstream source for much of the ACPI internals, but rather to the > > > > > Linux kernel itself. Hence, we introduce this flag so that we can > > make > > > > > ACPI_REDUCED_HARDWARE configurable. For the details of the > > discussion, > > > > > please refer to: > > http://www.spinics.net/lists/linux-acpi/msg46369.html > > > > > > > > > > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > > > > > Signed-off-by: Al Stone <al.stone@xxxxxxxxxx> > > > > > --- > > > > > drivers/acpi/Kconfig | 8 ++++++++ > > > > > include/acpi/platform/aclinux.h | 4 ++++ > > > > > 2 files changed, 12 insertions(+) > > > > > > > > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > > > > > index 589da05..7bbd3b0 100644 > > > > > --- a/drivers/acpi/Kconfig > > > > > +++ b/drivers/acpi/Kconfig > > > > > @@ -354,6 +354,14 @@ config ACPI_BGRT > > > > > data from the firmware boot splash. It will appear under > > > > > /sys/firmware/acpi/bgrt/ . > > > > > > > > > > +config ACPI_REDUCED_HARDWARE > > > > > + bool "Hardware-reduced ACPI support" > > > > > + depends on !(IA64 || X86) > > > > > > > > Why don't you use > > > > > > > > depends on (ARM || ARM64) > > > > > > > > here instead? > > > > > > > > > > hardware-reduced is not restricted to ARM platforms, that's why > > > > > > I used depends on !(IA64 || X86) here. > > > > So what exactly are the other platforms using ACPI in the Linux kernel? > > > > To telling the truth, I didn't see any other platform using ACPI except > IA64, X86 and ARM/ARM64, I just used depends on !(IA64 || x86) for > future purpose. However, if you used "depends on ARM || ARM64" (the parens are not needed BTW), the subsequent patches wouldn't need to check CONFIG_ARM/CONFIG_ARM64 in addition to CONFIG_ACPI_REDUCED_HARDWARE. That would simplify stuff somewhat. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
