Re: [PATCH v2 1/4] arm64: dts: ti: k3-am65-main: Disable RNG node

From: Jayesh Choudhary <j-choudhary@ti.com>
To: Andrew Davis <afd@ti.com>, Nishanth Menon <nm@ti.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Tero Kristo <kristo@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/4] arm64: dts: ti: k3-am65-main: Disable RNG node
Date: Tue, 30 Aug 2022 15:24:12 +0530	[thread overview]
Message-ID: <420e481d-0c91-1f0b-ea72-3a505a04330d@ti.com> (raw)
In-Reply-To: <20220823001136.10944-1-afd@ti.com>


On 23/08/22 05:41, Andrew Davis wrote:
> The hardware random number generator is used by OP-TEE and is access is
> denied to other users with SoC level bus firewalls. Any access to this
> device from Linux will result in firewall errors.
> 
> We could remove this node, but it is still valid device description,
> and it is possible it could be re-enabled in the bootloader if OP-TEE
> is not used. So only disable this node for now.
> 
> Signed-off-by: Andrew Davis <afd@ti.com>
> ---
> 
> Changes from v1:
>   - Added comment in DT
>   - Explained why it is only disabled in commit message
> 
>   arch/arm64/boot/dts/ti/k3-am65-main.dtsi | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> index 8919fede3cd7..b3e714e1abed 100644
> --- a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
> @@ -127,6 +127,7 @@ rng: rng@4e10000 {
>   			reg = <0x0 0x4e10000 0x0 0x7d>;
>   			interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
>   			clocks = <&k3_clks 136 1>;
> +			status = "disabled"; /* Used by OP-TEE */
>   		};
>   	};
>   

Reviewed-by: Jayesh Choudhary <j-choudhary@ti.com>