linux-kernel - Re: [PATCH 3/3] i2c: i2c-qcom-geni: Add support for 'assigned-performance-states'

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Date:   Fri, 15 Jan 2021 08:43:53 -0600
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Roja Rani Yarubandi <rojay@...eaurora.org>, ulf.hansson@...aro.org,
        viresh.kumar@...aro.org
Cc:     robh+dt@...nel.org, wsa@...nel.org, swboyd@...omium.org,
        dianders@...omium.org, saiprakash.ranjan@...eaurora.org,
        mka@...omium.org, akashast@...eaurora.org,
        msavaliy@....qualcomm.com, parashar@...eaurora.org,
        rnayak@...eaurora.org, linux-pm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, agross@...nel.org,
        linux-i2c@...r.kernel.org
Subject: Re: [PATCH 3/3] i2c: i2c-qcom-geni: Add support for
 'assigned-performance-states'

On Thu 24 Dec 05:12 CST 2020, Roja Rani Yarubandi wrote:

> @@ -629,6 +658,16 @@ static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
>  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
>  
>  	disable_irq(gi2c->irq);
> +
> +	/* Drop the assigned performance state */
> +	if (gi2c->assigned_pstate) {
> +		ret = dev_pm_genpd_set_performance_state(dev, 0);
> +		if (ret) {
> +			dev_err(dev, "Failed to set performance state\n");
> +			return ret;
> +		}
> +	}
> +

Ulf, Viresh, I think we discussed this at the time of introducing the
performance states.

The client's state does not affect if its performance_state should
be included in the calculation of the aggregated performance_state, so
each driver that needs to keep some minimum performance state needs to
have these two snippets.

Would it not make sense to on enable/disable re-evaluate the
performance_state and potentially reconfigure the hardware
automatically?

Regards,
Bjorn

>  	ret = geni_se_resources_off(&gi2c->se);
>  	if (ret) {
>  		enable_irq(gi2c->irq);
> @@ -654,6 +693,16 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> +	/* Set the assigned performance state */
> +	if (gi2c->assigned_pstate) {
> +		ret = dev_pm_genpd_set_performance_state(dev,
> +							 gi2c->assigned_pstate);
> +		if (ret) {
> +			dev_err(dev, "Failed to set performance state\n");
> +			return ret;
> +		}
> +	}
> +
>  	enable_irq(gi2c->irq);
>  	gi2c->suspended = 0;
>  	return 0;
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member 
> of Code Aurora Forum, hosted by The Linux Foundation
>