linux-kernel - Re: [PATCH v4] cpufreq/cppc: Remove the desired

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] [day] [month] [year] [list]

Message-ID: <20240613094245.cidth5miv4zxfg56@vireshk-i7>
Date: Thu, 13 Jun 2024 15:12:45 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Riwen Lu <luriwen@...mail.com>
Cc: ionela.voinescu@....com, rafael@...nel.org, pierre.gondois@....com,
	beata.michalska@....com, hotran@....com, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Riwen Lu <luriwen@...inos.cn>
Subject: Re: [PATCH v4] cpufreq/cppc: Remove the desired_perf compare when
 set target

On 12-06-24, 19:46, Riwen Lu wrote:
> From: Riwen Lu <luriwen@...inos.cn>
> 
> There is a case that desired_perf is exactly the same with the old perf,
> but the actual current freq is not.
> 
> This happened in S3 while the cpufreq governor is set to powersave.
> During cpufreq resume process, the booting CPU's new_freq obtained via
> .get() is the highest frequency, while the policy->cur and
> cpu->perf_ctrls.desired_perf are in the lowest level(powersave
> governor). Causing the warning: "CPU frequency out of sync:", and set
> policy->cur to new_freq.
> 
> Then the governor->limits() calls cppc_cpufreq_set_target() to
> configures the CPU frequency and returns directly because the
> desired_perf converted from target_freq is the same with
> cpu->perf_ctrls.desired_perf and both are the lowest_perf.
> 
> Since target_freq and policy->cur have been compared in
> __cpufreq_driver_target(), there's no need to compare desired_perf and
> cpu->perf_ctrls.desired_perf again in cppc_cpufreq_set_target() to
> ensure that the CPU frequency is properly configured.
> 
> Signed-off-by: Riwen Lu <luriwen@...inos.cn>

Applied. Thanks.

-- 
viresh