linux-kernel - Re: [PATCH] arm64: dts: allwinner: a64: Move CPU OPPs to the SoC dtsi file

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: <b07f1365a6f942297f7a3308fa628187@manjaro.org>
Date: Thu, 05 Sep 2024 14:38:53 +0200
From: Dragan Simic <dsimic@...jaro.org>
To: Andre Przywara <andre.przywara@....com>
Cc: Chen-Yu Tsai <wens@...e.org>, linux-sunxi@...ts.linux.dev,
 jernej.skrabec@...il.com, samuel@...lland.org,
 linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
 robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH] arm64: dts: allwinner: a64: Move CPU OPPs to the SoC dtsi
 file

Hello Andre,

On 2024-09-05 14:34, Andre Przywara wrote:
> On Thu, 5 Sep 2024 20:26:15 +0800
> Chen-Yu Tsai <wens@...e.org> wrote:
> 
>> Hi,
>> 
>> On Thu, Sep 5, 2024 at 8:17 PM Dragan Simic <dsimic@...jaro.org> 
>> wrote:
>> >
>> > Hello,
>> >
>> > Just checking, any further thoughts about this patch?
>> 
>> Sorry, but I feel like it's not really worth the churn. There's not
>> really a problem to be solved here. What you are arguing for is more
>> about aesthetics, and we could argue that having them separate makes
>> it easier to read and turn on/off.
> 
> Yeah, I agree. If a board wants to support OPPs, they just have to 
> include
> a single file and define the CPU regulator, and that's a nice opt-in,
> IMHO.
> But having this patch would make it quite hard to opt out, I believe. 
> For
> Linux there are probably ways to disable DVFS nevertheless, but I am 
> not
> sure this is true in an OS agnostic pure-DT-only way.

Thanks for your response.  The only thing that still makes me wonder
is why would a board want to opt out of DVFS?  Frankly, I'd consider
the design of the boards that must keep DVFS disabled broken.

> This could probably be solved, but same as Chen-Yu I don't see any good
> enough reason for this patch in the first place.
> 
>> And even though the GPU OPPs are in the dtsi, it's just one OPP acting
>> as a default clock rate.