Re: [PATCH] irqchip/gicv3: remove disabling redistributor and group1 non-secure interrupts

[Sudeep Holla]

Hi Christopher,

On 16/08/16 20:21, Christopher Covington wrote:
> Thanks Sudeep!
>
> On 08/16/2016 06:19 AM, Sudeep Holla wrote:
> > As per the GICv3 specification, to power down a processor using GICv3
> > and allow automatic power-on if an interrupt must be sent to a processor,
> > software must set Enable to zero for all interrupt groups(by writing
> > to GICC_CTLR or ICC_IGRPEN{0,1}_EL1/3 as appropriate.
> >
> > When commit 3708d52fc6bb ("irqchip: gic-v3: Implement CPU PM notifier")
> > was introduced there were no firmware implementations(in particular PSCI)
> > handling this.
> >
> > Linux kernel may not be aware of the CPU power state details and might
> > fail to identify the power states that require quiescing the CPU
> > interface. Even if it can be aware of those details, it can't determine
> > which CPU power state have been triggered at the platform level and how
> > the power control is implemented.
> >
> > This patch make disabling redistributor and group1 non-secure interrupts
> > in the power down path and re-enabling of redistributor in the power-up
> > path conditional. It will be handled in the kernel if and only if the
> > non-secure accesses are permitted to access and modify control registers.
> > It is left to the platform implementation otherwise.
> >
> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> > ---
> >  drivers/irqchip/irq-gic-v3.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> >
> > Hi Christopher,
> >
> > Can you check if ACPI processor idle works with this patch on QDF2432 ?
>
> This fixes the boot hang, and I see the usage and time files in cpuidle
> sysfs increasing on an idle system.
>
> Tested-by: Christopher Covington <cov@xxxxxxxxxxxxxx>

Thanks for testing.

I found the when CPU_PM is disabled, build triggers a warning. I will
move gic_dist_security_disabled inside the ifdef CPU_PM and post v2.

--
Regards,
Sudeep