linux-kernel - Re: [PATCH] arm64: dts: juno: align thermal zone names with bindings

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: <b9943188-b3f9-472f-bc60-e8e6e043ddf4@linaro.org>
Date: Wed, 3 Jan 2024 11:13:18 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Rob Herring <robh+dt@...nel.org>
Cc: Liviu Dudau <liviu.dudau@....com>, Sudeep Holla <sudeep.holla@....com>,
 Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
 Conor Dooley <conor+dt@...nel.org>, linux-arm-kernel@...ts.infradead.org,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] arm64: dts: juno: align thermal zone names with bindings

On 02/01/2024 19:09, Rob Herring wrote:
> On Sat, Dec 9, 2023 at 10:16 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@...aro.org> wrote:
>>
>> Thermal bindings require thermal zone node names to match
>> certain patterns:
>>
>>   juno.dtb: thermal-zones: 'big-cluster', 'gpu0', 'gpu1', 'little-cluster', 'pmic', 'soc'
>>     do not match any of the regexes: '^[a-zA-Z][a-zA-Z0-9\\-]{1,12}-thermal$', 'pinctrl-[0-9]+'
> 
> You've just traded this warning for these:
> 
>       6  thermal-zones: 'little-cluster-thermal' does not match any of
> the regexes: '^[a-zA-Z][a-zA-Z0-9\\-]{1,12}-thermal$',

Uh, now I wonder how did I see the warning going away.


> 'pinctrl-[0-9]+'
>       4  thermal-zones: gpu1-thermal: 'trips' is a required property
>       4  thermal-zones: gpu0-thermal: 'trips' is a required property
>       4  thermal-zones: big-cluster-thermal: 'trips' is a required property
> 
> Last I checked this, it looked like the length of the child names was
> limited because the thermal subsys uses the node names for its naming
> which is limited to 20 chars (with null). Though the regex here allows
> for 21 chars without nul. Looks like a double off by one error.

Yes, that's another issue.

> 
> The thought I had at the time was to make the kernel drop '-thermal'
> from its names. Might be an (Linux) ABI issue if userspace cares (I
> think it shouldn't). Also, I'm not sure how the kernel handles the
> names overflowing. Maybe it is fine and we can just extend the length
> in the schema from 12 to 18 (plus the 1 starting char).

The name is used in the "/sys/class/thermal/thermal_zone0/type" file, so
actually some userspace could depend on it, but it would be affected
anyway by my renaming of nodes.

Best regards,
Krzysztof