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Subject: Re: [PATCH v1 1/1] ARM: dts: rockchip: set crypto default disabled on
 rk3288
To:     Heiko Stuebner <heiko@sntech.de>
Cc:     mark.rutland@arm.com, robh+dt@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org
References: <20190827071439.14767-1-zhangzj@rock-chips.com>
 <4806912.UyKsYhR33o@phil>
From:   Elon Zhang <zhangzj@rock-chips.com>
Message-ID: <3b9cbffa-291e-fc95-bce6-5b24f5fd860d@rock-chips.com>
Date:   Thu, 29 Aug 2019 19:31:00 +0800
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Hi Heiko,

On 8/27/2019 22:28, Heiko Stuebner wrote:
> Hi,
>
> Am Dienstag, 27. August 2019, 09:14:39 CEST schrieb Elon Zhang:
>> Not every board needs to enable crypto node, so the node should
>> be set default disabled in rk3288.dtsi and enabled in specific
>> board dts file.
> Can you give a bit more rationale here? There would need to be a very
> specific reason because of the following:
>
> The crypto module is not wired to some board-specific components,
> so its usability does not depend on the specific board at all.
> Instead every board can just use it out of the box and the devicetree
> is supposed to describe the hardware and is _not_ meant as a space
> for user configuration.

Right for almost all normal hardware modules but the crypto module was 
designed

for secure world. As a result,  the crypto module will become 
inaccessible for linux

kernel if secure world enable it.

We plan to enable the crypto module in secure world so we should set 
crypto module

default disabled in linux kernel.

>
> So in fact the status property should probably go away completely from
> the crypto node, as it's usable out of the box in all cases.
>
>
> Heiko
>
>
>
>> Signed-off-by: Elon Zhang <zhangzj@rock-chips.com>
>> ---
>>   arch/arm/boot/dts/rk3288.dtsi | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
>> index cc893e154fe5..d509aa24177c 100644
>> --- a/arch/arm/boot/dts/rk3288.dtsi
>> +++ b/arch/arm/boot/dts/rk3288.dtsi
>> @@ -984,7 +984,7 @@
>>   		clock-names = "aclk", "hclk", "sclk", "apb_pclk";
>>   		resets = <&cru SRST_CRYPTO>;
>>   		reset-names = "crypto-rst";
>> -		status = "okay";
>> +		status = "disabled";
>>   	};
>>   
>>   	iep_mmu: iommu@ff900800 {
>>
>
>
>
>
>
>