linux-kernel - Re: [PATCH v7 15/19] PM / devfreq: tegra30: Disable consecutive interrupts when appropriate

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Date:   Fri, 1 Nov 2019 16:01:05 +0900
From:   Chanwoo Choi <cw00.choi@...sung.com>
To:     Dmitry Osipenko <digetx@...il.com>,
        Thierry Reding <thierry.reding@...il.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        Peter Geis <pgwipeout@...il.com>
Cc:     linux-pm@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 15/19] PM / devfreq: tegra30: Disable consecutive
 interrupts when appropriate

On 19. 10. 30. 오전 7:00, Dmitry Osipenko wrote:
> Consecutive interrupts should be disabled when boosting is completed.
> 
> Currently the disabling of "lower" interrupt happens only for MCCPU
> monitor that uses dependency threshold, but even in a case of MCCPU the
> interrupt isn't getting disabled if CPU's activity is above the threshold.
> This results in a lot of dummy interrupt requests. The boosting feature is
> used by both MCCPU and MCALL, boosting should be stopped once it reaches 0
> for both of the monitors and regardless of the activity level.
> 
> The boosting stops to grow once the maximum limit is hit and thus the
> "upper" interrupt needs to be disabled when the limit is reached.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index a9336cf4b37a..b745a973c35a 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -259,8 +259,10 @@ static void actmon_isr_device(struct tegra_devfreq *tegra,
>  
>  		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
>  
> -		if (dev->boost_freq >= tegra->max_freq)
> +		if (dev->boost_freq >= tegra->max_freq) {
> +			dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
>  			dev->boost_freq = tegra->max_freq;
> +		}
>  	} else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
>  		/*
>  		 * new_boost = old_boost * down_coef
> @@ -271,15 +273,10 @@ static void actmon_isr_device(struct tegra_devfreq *tegra,
>  
>  		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
>  
> -		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1))
> -			dev->boost_freq = 0;
> -	}
> -
> -	if (dev->config->avg_dependency_threshold) {
> -		if (dev->avg_count >= dev->config->avg_dependency_threshold)
> -			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
> -		else if (dev->boost_freq == 0)
> +		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) {
>  			dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
> +			dev->boost_freq = 0;
> +		}
>  	}
>  
>  	device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL);
> 

Reviewed-by: Chanwoo Choi <cw00.choi@...sung.com>

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics