linux-kernel - Re: [Patch v2 2/2] cpufreq: tegra194: use refclk delta based loop instead of udelay

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: <8c26f493-76d4-086e-c353-2f60a4ef7a72@nvidia.com>
Date:   Fri, 1 Sep 2023 18:59:24 +0100
From:   Jon Hunter <jonathanh@...dia.com>
To:     Sumit Gupta <sumitg@...dia.com>, rafael@...nel.org,
        viresh.kumar@...aro.org, linux-pm@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     treding@...dia.com, bbasu@...dia.com, amiettinen@...dia.com
Subject: Re: [Patch v2 2/2] cpufreq: tegra194: use refclk delta based loop
 instead of udelay


On 01/09/2023 17:41, Sumit Gupta wrote:
> Use reference clock count based loop instead of "udelay()" for
> sampling of counters to improve the accuracy of re-generated CPU
> frequency. "udelay()" internally calls "WFE" which stops the
> counters and results in bigger delta between the last set freq
> and the re-generated value from counters. The counter sampling
> window used in loop is the minimum number of reference clock
> cycles which is known to give a stable value of CPU frequency.
> The change also helps to reduce the sampling window from "500us"
> to "<50us".
> 
> Suggested-by: Antti Miettinen <amiettinen@...dia.com>
> Signed-off-by: Sumit Gupta <sumitg@...dia.com>
> ---

Same here.

Jon

-- 
nvpublic