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

[Marc Zyngier <marc.zyngier-5wv7dgnIgG8@public.gmane.org>]

On 27/11/14 15:34, Liviu Dudau wrote:
> 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-5wv7dgnIgG8@public.gmane.org>
>>> ---
>>>
>>> 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.
> 
> BTW, should I also update the bindings example to get this right?

Definitely. I'm pretty sure I got it wrong too at some point...

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