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Message-ID: <da9f8b90-e4d1-5893-f656-1bb0221ea7f7@mediatek.com>
Date:   Mon, 24 Oct 2022 14:18:05 +0800
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Subject: Re: [PATCH v2] arm64: dts: mediatek: mt8195-demo: fix the memory size
 of node secmon
Content-Language: en-US
To:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Fabien Parent <fparent@baylibre.com>,
        <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
CC:     Miles Chen <miles.chen@mediatek.com>,
        Bear Wang <bear.wang@mediatek.com>,
        Pablo Sun <pablo.sun@mediatek.com>,
        Macpaul Lin <macpaul@gmail.com>, <linux-usb@vger.kernel.org>,
        <stable@vger.kernel.org>, Matthias Brugger <mbrugger@suse.com>
References: <20220922091648.2821-1-macpaul.lin@mediatek.com>
 <20220929084714.15143-1-macpaul.lin@mediatek.com>
From:   Macpaul Lin <macpaul.lin@mediatek.com>
In-Reply-To: <20220929084714.15143-1-macpaul.lin@mediatek.com>
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Precedence: bulk

On 9/29/22 16:47, Macpaul Lin wrote:
> The size of device tree node secmon (bl31_secmon_reserved) was
> incorrect. It should be increased to 2MiB (0x200000).
> 
> The origin setting will cause some abnormal behavior due to
> trusted-firmware-a and related firmware didn't load correctly.
> The incorrect behavior may vary because of different software stacks.
> For example, it will cause build error in some Yocto project because
> it will check if there was enough memory to load trusted-firmware-a
> to the reserved memory.
> 
> When mt8195-demo.dts sent to the upstream, at that time the size of
> BL31 was small. Because supported functions and modules in BL31 are
> basic sets when the board was under early development stage.
> 
> Now BL31 includes more firmwares of coprocessors and maturer functions
> so the size has grown bigger in real applications. According to the value
> reported by customers, we think reserved 2MiB for BL31 might be enough
> for maybe the following 2 or 3 years.

Dear Matthias, sorry for a gentle reminder. MediaTek hope this simple 
fix could be applied to 6.1-rc and be picked-up to current stable tree 
after v5.19. Thanks a lot.

> Cc: stable@vger.kernel.org      # v5.19
> Fixes: 6147314aeedc ("arm64: dts: mediatek: Add device-tree for MT8195 Demo board")
> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
> Reviewed-by: Miles Chen <miles.chen@mediatek.com>
> ---
> Changes for v2
>   - Add more information about the size difference for BL31 in commit message.
>     Thanks for Miles's review.
> 
>   arch/arm64/boot/dts/mediatek/mt8195-demo.dts | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt8195-demo.dts b/arch/arm64/boot/dts/mediatek/mt8195-demo.dts
> index 4fbd99eb496a..dec85d254838 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8195-demo.dts
> +++ b/arch/arm64/boot/dts/mediatek/mt8195-demo.dts
> @@ -56,10 +56,10 @@
>   		#size-cells = <2>;
>   		ranges;
>   
> -		/* 192 KiB reserved for ARM Trusted Firmware (BL31) */
> +		/* 2 MiB reserved for ARM Trusted Firmware (BL31) */
>   		bl31_secmon_reserved: secmon@54600000 {
>   			no-map;
> -			reg = <0 0x54600000 0x0 0x30000>;
> +			reg = <0 0x54600000 0x0 0x200000>;
>   		};
>   
>   		/* 12 MiB reserved for OP-TEE (BL32)

Regards,
Macpaul Lin