Commit 90a21ff5 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Eduardo Valentin
Browse files

imx: thermal: imx_get_temp might be called before sensor clock is prepared 



imx_get_temp might be called before the sensor clock is prepared
thus resulting in a timeout of the first attempt to read temp:
thermal thermal_zone0: failed to read out thermal zone 0
Happened to me on a Utilite Standard with IMX6 Dual SoC.

Reason is that in imx_thermal_probe thermal_zone_device_register
is called before the sensor clock is prepared.
thermal_zone_device_register however calls
thermal_zone_device_update which eventually calls imx_get_temp.

Fix this by preparing the clock before calling
thermal_zone_device_register.

Signed-off-by: default avatarHeiner Kallweit <heiner.kallweit@web.de>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent 1d6a2777

drivers/thermal/imx_thermal.c

+25 −16
Original line number Diff line number Diff line
@@ -525,24 +525,16 @@ static int imx_thermal_probe(struct platform_device *pdev) 
		return ret;

	}



	data->tz = thermal_zone_device_register("imx_thermal_zone",

						IMX_TRIP_NUM,

						BIT(IMX_TRIP_PASSIVE), data,

						&imx_tz_ops, NULL,

						IMX_PASSIVE_DELAY,

						IMX_POLLING_DELAY);

	if (IS_ERR(data->tz)) {

		ret = PTR_ERR(data->tz);

	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(data->thermal_clk)) {

		ret = PTR_ERR(data->thermal_clk);

		if (ret != -EPROBE_DEFER)

			dev_err(&pdev->dev,

			"failed to register thermal zone device %d\n", ret);

				"failed to get thermal clk: %d\n", ret);

		cpufreq_cooling_unregister(data->cdev);

		return ret;

	}



	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(data->thermal_clk)) {

		dev_warn(&pdev->dev, "failed to get thermal clk!\n");

	} else {

	/*

	 * Thermal sensor needs clk on to get correct value, normally

	 * we should enable its clk before taking measurement and disable
@@ -551,8 +543,25 @@ static int imx_thermal_probe(struct platform_device *pdev) 
	 * need to keep the clk always on for alarm function.

	 */

	ret = clk_prepare_enable(data->thermal_clk);

		if (ret)

			dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret);

	if (ret) {

		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);

		cpufreq_cooling_unregister(data->cdev);

		return ret;

	}



	data->tz = thermal_zone_device_register("imx_thermal_zone",

						IMX_TRIP_NUM,

						BIT(IMX_TRIP_PASSIVE), data,

						&imx_tz_ops, NULL,

						IMX_PASSIVE_DELAY,

						IMX_POLLING_DELAY);

	if (IS_ERR(data->tz)) {

		ret = PTR_ERR(data->tz);

		dev_err(&pdev->dev,

			"failed to register thermal zone device %d\n", ret);

		clk_disable_unprepare(data->thermal_clk);

		cpufreq_cooling_unregister(data->cdev);

		return ret;

	}



	/* Enable measurements at ~ 10 Hz */

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