Re: [PATCH] arm64: ARM: Fix the Generic Timers interrupt active level description

From: Liviu Dudau
Date: Thu Nov 27 2014 - 10:33:33 EST


On Thu, Nov 27, 2014 at 02:43:38PM +0000, Marc Zyngier wrote:
> On 27/11/14 14:36, Liviu Dudau wrote:
> > The Cortex-A5x TRM states in paragraph "9.2 Generic Timer functional
> > description" that generic timers provide an active-LOW interrupt
> > output. Fix the device trees to correctly describe this.
> >
> > While doing this update the CPU mask to match the number of described
> > CPUs as well.
> >
> > Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> > ---
> >
> > Arnd, Olof: This is on top of linux-next/master as it patches the Juno
> > as well as all the other ARM DTs.
> >
> > arch/arm64/boot/dts/arm/foundation-v8.dts | 8 ++++----
> > arch/arm64/boot/dts/arm/juno.dts | 8 ++++----
> > arch/arm64/boot/dts/arm/rtsm_ve-aemv8a.dts | 8 ++++----
> > 3 files changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/arm/foundation-v8.dts b/arch/arm64/boot/dts/arm/foundation-v8.dts
> > index 4a06090..27f3296 100644
> > --- a/arch/arm64/boot/dts/arm/foundation-v8.dts
> > +++ b/arch/arm64/boot/dts/arm/foundation-v8.dts
> > @@ -78,10 +78,10 @@
> >
> > timer {
> > compatible = "arm,armv8-timer";
> > - interrupts = <1 13 0xff01>,
> > - <1 14 0xff01>,
> > - <1 11 0xff01>,
> > - <1 10 0xff01>;
> > + interrupts = <1 13 0xf08>,
> > + <1 14 0xf08>,
> > + <1 11 0xf08>,
> > + <1 10 0xf08>;
> > clock-frequency = <100000000>;
> > };
> >
> > diff --git a/arch/arm64/boot/dts/arm/juno.dts b/arch/arm64/boot/dts/arm/juno.dts
> > index 097ecc4..cb3073e 100644
> > --- a/arch/arm64/boot/dts/arm/juno.dts
> > +++ b/arch/arm64/boot/dts/arm/juno.dts
> > @@ -98,10 +98,10 @@
> >
> > timer {
> > compatible = "arm,armv8-timer";
> > - interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_EDGE_RISING)>,
> > - <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_EDGE_RISING)>,
> > - <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_EDGE_RISING)>,
> > - <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_EDGE_RISING)>;
> > + interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
> > + <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
> > + <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>,
> > + <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>;
> > };
> >
> > pmu {
> > diff --git a/arch/arm64/boot/dts/arm/rtsm_ve-aemv8a.dts b/arch/arm64/boot/dts/arm/rtsm_ve-aemv8a.dts
> > index 572005e..efc59b3 100644
> > --- a/arch/arm64/boot/dts/arm/rtsm_ve-aemv8a.dts
> > +++ b/arch/arm64/boot/dts/arm/rtsm_ve-aemv8a.dts
> > @@ -81,10 +81,10 @@
> >
> > timer {
> > compatible = "arm,armv8-timer";
> > - interrupts = <1 13 0xff01>,
> > - <1 14 0xff01>,
> > - <1 11 0xff01>,
> > - <1 10 0xff01>;
> > + interrupts = <1 13 0xf08>,
> > + <1 14 0xf08>,
> > + <1 11 0xf08>,
> > + <1 10 0xf08>;
> > clock-frequency = <100000000>;
> > };
> >
> >
>
> Sorry, but that's wrong. Despite the *cores* having an level-low output,
> the GIC only triggers on *level-high*. Yes, there is probably an
> inverter in between.

Hah, one can never read enough specs to get the right answer!

I'll update the patch.

Best regards,
Liviu

>
> M.
> --
> Jazz is not dead. It just smells funny...
>

--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
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