linux-kernel - Re: [PATCH v2] ARM: dts: Move syscon reboot/poweroff to common dtsi for Exynos

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <56C3D99C.3090403@osg.samsung.com>
Date:	Tue, 16 Feb 2016 23:23:24 -0300
From:	Javier Martinez Canillas <javier@....samsung.com>
To:	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	linux-kernel@...r.kernel.org
Cc:	devicetree@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
	Andi Shyti <andi.shyti@...sung.com>,
	Alim Akhtar <alim.akhtar@...sung.com>,
	Kukjin Kim <kgene@...nel.org>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2] ARM: dts: Move syscon reboot/poweroff to common dtsi
 for Exynos

Hello Krzysztof,

On 02/16/2016 11:13 PM, Krzysztof Kozlowski wrote:

[snip]

>> diff --git a/arch/arm/boot/dts/exynos-syscon-restart.dtsi b/arch/arm/boot/dts/exynos-syscon-restart.dtsi
>> new file mode 100644
>> index 000000000000..09a2040054ed
>> --- /dev/null
>> +++ b/arch/arm/boot/dts/exynos-syscon-restart.dtsi
>> @@ -0,0 +1,27 @@
>> +/*
>> + * Samsung's Exynos SoC syscon reboot/poweroff nodes common definition.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +/ {
>> +	soc {
>> +		compatible = "simple-bus";
>
> The exynos4 does not have soc node. I wonder whether we should provide
> here also address and size:
>                  #address-cells = <1>;
>                  #size-cells = <1>;
> 		ranges;
>
> Without this it works fine but that does not look correct enough.
>
> A minor effect of this patch on Exynos4 is that syscon-poweroff/reboot
> are now the only children of "soc" simple-bus (rest of platform devices
> is not)... but this is not a problem.
>
> Works fine so only the question about cells/ranges remains. Any comments?
>

I in fact had the #address-cells and #size-cells at the beginning but then
realized that both the syscon-poweroff and syscon-reboot nodes didn't have
a reg property so it felt strange to me to have those.

Also, I thought that maybe a SoC dtsi may need a different #address-cells
and #size-cells for the other child nodes so having those in this dtsi
could override the values in the SoC dtsi depending where is included.

So I thought it could do more harm than good but I've no strong opinion
and can add those if you prefer.

> Best regards,
> Krzysztof
>
>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America