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Subject: Re: [PATCH v5 3/4] DT/arm,gic-v3-its: add reset-on-suspend property
To:     Derek Basehore <dbasehore@chromium.org>,
        linux-kernel@vger.kernel.org
Cc:     Soby.Mathew@arm.com, sudeep.holla@arm.com,
        devicetree@vger.kernel.org, robh+dt@kernel.org,
        mark.rutland@arm.com, linux-pm@vger.kernel.org,
        rafael.j.wysocki@intel.com, tglx@linutronix.de,
        briannorris@chromium.org
References: <20180207014117.62611-1-dbasehore@chromium.org>
 <20180207014117.62611-4-dbasehore@chromium.org>
From:   Marc Zyngier <marc.zyngier@arm.com>
Organization: ARM Ltd
Message-ID: <b4c7bc62-6861-3851-513e-be8d7a440c91@arm.com>
Date:   Wed, 7 Feb 2018 09:21:59 +0000
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On 07/02/18 01:41, Derek Basehore wrote:
> This adds documentation for the new reset-on-suspend property. This
> property enables saving and restoring the ITS for when it loses state
> in system suspend.
> 
> Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> ---
>  Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> index 0a57f2f4167d..a470147d4f14 100644
> --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> @@ -78,6 +78,9 @@ These nodes must have the following properties:
>  Optional:
>  - socionext,synquacer-pre-its: (u32, u32) tuple describing the untranslated
>    address and size of the pre-ITS window.
> +- reset-on-suspend: Boolean property. Indicates that the ITS state is
> +  reset on suspend. The state is then saved on suspend and restored on
> +  resume.

By whom? It is important to be clear about the respective
responsibilities, as this forms a binding contract between firmware and OS.

Mark: Can you have a look at how to formulate this? I'm not sure we have
other instances of a non-architected behaviour involving FW
participation, aside from PSCI.

>  
>  The main GIC node must contain the appropriate #address-cells,
>  #size-cells and ranges properties for the reg property of all ITS
> 

Thanks,

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