linux-kernel - Re: [PATCH 2/2] cpufreq: CPPC: Fix error handling in cppc_scale_freq

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CAFivqmJyYJ+d+TH4qYBKf_5t-AqWZuzgk2H_4nHmynTjoUHnYQ@mail.gmail.com>
Date: Mon, 4 Aug 2025 18:12:34 -0700
From: Prashant Malani <pmalani@...gle.com>
To: Jie Zhan <zhanjie9@...ilicon.com>
Cc: Viresh Kumar <viresh.kumar@...aro.org>, Bowen Yu <yubowen8@...wei.com>, rafael@...nel.org, 
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org, linuxarm@...wei.com, 
	jonathan.cameron@...wei.com, lihuisong@...wei.com, zhenglifeng1@...wei.com, 
	Beata Michalska <beata.michalska@....com>, Ionela Voinescu <ionela.voinescu@....com>
Subject: Re: [PATCH 2/2] cpufreq: CPPC: Fix error handling in cppc_scale_freq_workfn()

On Sun, 3 Aug 2025 at 23:21, Jie Zhan <zhanjie9@...ilicon.com> wrote
> On 01/08/2025 16:58, Prashant Malani wrote:
> > This begs the question: why is this work function being scheduled
> > for CPUs that are in reset or offline/powered-down at all?
> > IANAE but it sounds like it would be better to add logic to ensure this
> > work function doesn't get scheduled/executed for CPUs that
> > are truly offline/powered-down or in reset.
> Yeah good question.  We may discuss that on your thread.

OK.
Quickly looking around, it sounds having in the CPPC tick function [1]
might be a better option (one probably doesn't want to lift it beyond the
CPPC layer, since other drivers might have different behaviour).
One can add a cpu_online/cpu_enabled check there.

[1] https://elixir.bootlin.com/linux/v6.16/source/include/linux/cpumask.h#L1233

-- 
-Prashant