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Date: Thu, 27 Jul 2023 15:57:59 +0100
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Subject: Re: [PATCH] arm64: dts: pinephone: Add pstore support for PinePhone
 A64
To: Andrey Skvortsov <andrej.skvortzov@gmail.com>,
 Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
 Jernej Skrabec <jernej.skrabec@gmail.com>,
 Samuel Holland <samuel@sholland.org>, Kees Cook <keescook@chromium.org>,
 Tony Luck <tony.luck@intel.com>, "Guilherme G. Piccoli"
 <gpiccoli@igalia.com>, devicetree@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev,
 linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
 Jarrah Gosbell <kernel@undef.tools>,
 Arnaud Ferraris <arnaud.ferraris@collabora.com>
References: <20230724213457.24593-1-andrej.skvortzov@gmail.com>
Content-Language: en-US
From: Andre Przywara <andre.przywara@arm.com>
In-Reply-To: <20230724213457.24593-1-andrej.skvortzov@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
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Hi,

On 24/07/2023 22:34, Andrey Skvortsov wrote:
> This patch reserves some memory in the DTS and sets up a
> pstore device tree node to enable pstore support.
> 
> Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
> 
> Gbp-Pq: Topic pinephone
> Gbp-Pq: Name 0161-arm64-dts-pinephone-Add-pstore-support-for-PinePhone.patch
> ---
>   .../boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
> index 87847116ab6d..84f9410b0b70 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
> @@ -19,6 +19,22 @@ aliases {
>   		serial0 = &uart0;
>   	};
>   
> +	reserved-memory {
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges;
> +
> +		pstore_mem: ramoops@61000000 {
> +			compatible = "ramoops";
> +			reg = <0x61000000 0x100000>;

So what's the significance of this address? That's 528MB into DRAM, so 
somewhat in the middle of it, fragmenting the physical address space.
And is there any other firmware component that needs to know about this 
address?

Cheers,
Andre


> +			record-size = <0x20000>;
> +			console-size = <0x20000>;
> +			ftrace-size = <0x20000>;
> +			pmsg-size = <0x20000>;
> +			ecc-size = <16>;
> +		};
> +	};
> +
>   	backlight: backlight {
>   		compatible = "pwm-backlight";
>   		pwms = <&r_pwm 0 50000 PWM_POLARITY_INVERTED>;