Message-ID: <7a01c3f6-3800-472e-e18f-82af1b3f8d9e@linaro.org>
Date:   Fri, 27 Jan 2023 22:03:51 +0100
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Subject: Re: [PATCH v9 5/5] thermal: mediatek: add delay after thermal banks
 initialization
Content-Language: en-US
To:     Amjad Ouled-Ameur <aouledameur@baylibre.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Fabien Parent <fparent@baylibre.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Rob Herring <robh@kernel.org>,
        Markus Schneider-Pargmann <msp@baylibre.com>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Michael Kao <michael.kao@mediatek.com>
References: <20221018-up-i350-thermal-bringup-v9-0-55a1ae14af74@baylibre.com>
 <20221018-up-i350-thermal-bringup-v9-5-55a1ae14af74@baylibre.com>
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
In-Reply-To: <20221018-up-i350-thermal-bringup-v9-5-55a1ae14af74@baylibre.com>
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Precedence: bulk

On 27/01/2023 16:44, Amjad Ouled-Ameur wrote:
> Thermal sensor reads performed immediately after thermal bank
> initialization returns bogus values. This is currently tackled by returning
> 0 if the temperature is bogus (exceeding 200000).
> 
> Instead, add a delay between the bank init and the thermal zone device
> register to properly fix this.
> 
> Signed-off-by: Michael Kao <michael.kao@mediatek.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>   drivers/thermal/mtk_thermal.c | 11 +++--------
>   1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> index b8e06f6c7c42..ab7db385afb3 100644
> --- a/drivers/thermal/mtk_thermal.c
> +++ b/drivers/thermal/mtk_thermal.c
> @@ -730,14 +730,6 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
>   
>   		temp = mt->raw_to_mcelsius(mt, i, raw);
>   
> -		/*
> -		 * The first read of a sensor often contains very high bogus
> -		 * temperature value. Filter these out so that the system does
> -		 * not immediately shut down.
> -		 */
> -		if (temp > 200000)
> -			temp = 0;
> -
>   		if (temp > max)
>   			max = temp;
>   	}
> @@ -1160,6 +1152,9 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, mt);
>   
> +	// Delay for thermal banks to be ready

Coding style for comments is : /* */

No need to resend, I'll take care of changing the comment format.

> +	msleep(30);
> +
>   	tzdev = devm_thermal_of_zone_register(&pdev->dev, 0, mt,
>   					      &mtk_thermal_ops);
>   	if (IS_ERR(tzdev)) {
> 

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