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

From: Marc Zyngier
Date: Thu Nov 27 2014 - 09:43:53 EST


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.

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