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

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Message-ID: <59d37960-cf19-4b10-802f-59d42496c133@arm.com>
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?

[...]