Re: [PATCH v10 7/7] ACPI : enable ACPI_PROCESSOR_IDLE on ARM64

[Sudeep Holla]

Hi Christopher,

On 15/08/16 15:47, Christopher Covington wrote:
> Hi Sudeep,
>
> On 08/02/2016 09:00 AM, Sudeep Holla wrote:
> > On 29/07/16 20:05, Christopher Covington wrote:
> > > Hi Sudeep,
> > >
> > > On 07/19/2016 01:52 PM, Sudeep Holla wrote:
> > > > Now that ACPI processor idle driver supports LPI(Low Power Idle), lets
> > > > enable ACPI_PROCESSOR_IDLE for ARM64 too.
> > > >
> > > > This patch just removes the IA64 and X86 dependency on
> > > > ACPI_PROCESSOR_IDLE
> > > >
> > > > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> > > > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> > > > ---
> > > >  drivers/acpi/Kconfig | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > > > index 1358fb7d7a68..d74275c0f374 100644
> > > > --- a/drivers/acpi/Kconfig
> > > > +++ b/drivers/acpi/Kconfig
> > > > @@ -238,7 +238,7 @@ config ACPI_CPPC_LIB
> > > >  config ACPI_PROCESSOR
> > > >      tristate "Processor"
> > > >      depends on X86 || IA64 || ARM64
> > > > -    select ACPI_PROCESSOR_IDLE if X86 || IA64
> > > > +    select ACPI_PROCESSOR_IDLE
> > > >      select ACPI_CPU_FREQ_PSS if X86 || IA64
> > > >      default y
> > > >      help
> > >
> > > This causes a boot hang on QDF2432. cpuidle.off=1 works around the
> > > problem. I understand you're working on a fix to the problem in GICv3
> > > code. If there's anything I can do to help, please let me know.
> >
> > Sorry for the late response, I was away. Yes it's to do with GICv3 and
> > retention states. I exchanged mails with QCOM guys in private. To
> > summarize:
> >
> > We don't need any additional support in Linux to support that. Infact we
> > need to remove disabling the redistributor in the powerdown path. PSCI
> > implementation also do the same for Group0(aka secure/EL3 interrupts)
> > and we currently do that for Group1(aka EL1N interrupts) in Linux. The
> > plan was to move that to EL3 code, to align with GICv2 code.
> >
> > Hence the changes in Linux is just removal of the GICv3 PM notifier
> > partially. I will need to check with Trusted Firmware team and do some
> > testing before I post that change. I will plan to do that later this week.
>
> Have you been able to make progress on the fix? If there's anything we
> can do to help, please let us know. If the fix is going to take a while,
> would it be appropriate to revert the Kconfig change until it is in place?

Thanks for the remainder. Yes I will post this week, I posted arm
trusted firmware patch first and was waiting it to be pulled.

--
Regards,
Sudeep