linux-kernel - Re: [RESEND][PATCH v2 4/4] soc: samsung: exynos-asv: Update Energy Model after adjusting voltage

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]

Date: Tue, 26 Mar 2024 12:20:01 +0100
From: Dietmar Eggemann <dietmar.eggemann@....com>
To: Lukasz Luba <lukasz.luba@....com>, linux-kernel@...r.kernel.org,
 linux-pm@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org, sboyd@...nel.org, nm@...com,
 linux-samsung-soc@...r.kernel.org, daniel.lezcano@...aro.org,
 rafael@...nel.org, viresh.kumar@...aro.org, krzysztof.kozlowski@...aro.org,
 alim.akhtar@...sung.com, m.szyprowski@...sung.com, mhiramat@...nel.org
Subject: Re: [RESEND][PATCH v2 4/4] soc: samsung: exynos-asv: Update Energy
 Model after adjusting voltage

On 22/03/2024 12:08, Lukasz Luba wrote:

[...]

> @@ -97,9 +98,17 @@ static int exynos_asv_update_opps(struct exynos_asv *asv)
>  			last_opp_table = opp_table;
>  
>  			ret = exynos_asv_update_cpu_opps(asv, cpu);
> -			if (ret < 0)
> +			if (!ret) {
> +				/*
> +				 * When the voltage for OPPs successfully
> +				 * changed, update the EM power values to
> +				 * reflect the reality and not use stale data

At this point, can we really say that the voltage has changed?

  exynos_asv_update_cpu_opps()

    ...
    ret = dev_pm_opp_adjust_voltage()
    if (!ret)
      em_dev_update_chip_binning()
    ...

dev_pm_opp_adjust_voltage() also returns 0 when the voltage value stays
the same?

[...]