Re: [PATCH v1] thermal: imx: Make trip point offset configurable

From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: Francesco Dolcini <francesco.dolcini@toradex.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	l.stach@pengutronix.de, linux-pm@vger.kernel.org
Cc: "Rafael J . Wysocki" <rafael@kernel.org>,
	Fabio Estevam <festevam@gmail.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Amit Kucheria <amitk@kernel.org>,
	Jon Nettleton <jon@solid-run.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Shawn Guo <shawnguo@kernel.org>,
	Tim Harvey <tharvey@gateworks.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v1] thermal: imx: Make trip point offset configurable
Date: Mon, 16 May 2022 21:06:10 +0200	[thread overview]
Message-ID: <92ae0fd5-f827-ae3c-bbef-d551c9fa5b76@pengutronix.de> (raw)
In-Reply-To: <20220516190001.147919-1-francesco.dolcini@toradex.com>

On 16.05.22 21:00, Francesco Dolcini wrote:
> Currently the imx thermal driver has a hardcoded critical temperature
> value offset of 5 Celsius degrees from the actual SoC maximum
> temperature.
> 
> This affects applications and systems designed to be working on this close
> to the limit, but yet valid, temperature range.
> 
> Given that there is no single value that will fit all the use cases make
> the critical trip point offset from the max temperature configurable
> using a newly added trip_offset module parameter, passive trip point is
> set to 5 Celsius degrees less than the critical. By default the
> system behaves exactly as before.
> 
> Link: https://lore.kernel.org/all/20220420091300.179753-1-francesco.dolcini@toradex.com/
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
>  drivers/thermal/imx_thermal.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index 16663373b682..42d1f8a3eccb 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -86,6 +86,10 @@ enum imx_thermal_trip {
>  #define TEMPMON_IMX6SX			2
>  #define TEMPMON_IMX7D			3
>  
> +static int trip_offset = 5;
> +module_param(trip_offset, int, 0444);

Is this being r--r--r-- intended?

> +MODULE_PARM_DESC(trip_offset, "Critical trip point offset from CPU max temp in Celsius degrees (default 5)");
> +
>  struct thermal_soc_data {
>  	u32 version;
>  
> @@ -504,11 +508,11 @@ static void imx_init_temp_grade(struct platform_device *pdev, u32 ocotp_mem0)
>  	}
>  
>  	/*
> -	 * Set the critical trip point at 5 °C under max
> -	 * Set the passive trip point at 10 °C under max (changeable via sysfs)
> +	 * Set the critical trip point at 5 °C under max (changeable via module param)
> +	 * Set the passive trip point at 5 °C under critical (changeable via sysfs)
>  	 */
> -	data->temp_critical = data->temp_max - (1000 * 5);
> -	data->temp_passive = data->temp_max - (1000 * 10);
> +	data->temp_critical = data->temp_max - (1000 * trip_offset);
> +	data->temp_passive = data->temp_critical - (1000 * 5);
>  }
>  
>  static int imx_init_from_tempmon_data(struct platform_device *pdev)

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