[PATCH 2/5] thermal: exynos: Fix first temperature read after registering sensor

Krzysztof Kozlowski
2015-10-08T05:34:03Z

Thermal core could not read the temperature after registering the
thermal sensor with thermal_zone_of_sensor_register() because the driver
was not yet initialized.

The call trace looked like:
exynos_tmu_probe()
thermal_zone_of_sensor_register()
of_thermal_set_mode()
thermal_zone_device_update()
exynos_get_temp()
if (!data->tmu_read) return -EINVAL;
exynos_map_dt_data()
data->tmu_read = ...

This produced an error in dmesg:
thermal thermal_zone0: failed to read out thermal zone (-22)

Register the thermal_zone_device later, after parsing Device Tree and
enabling necessary clocks, but before calling exynos_tmu_initialize()
which uses the registered thermal_zone_device.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 3b6a1a805f34 ("thermal: samsung: core: Exynos TMU rework to use device tree for configuration")
---
drivers/thermal/samsung/exynos_tmu.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 23f4320f8ef7..bc71a61f0c4a 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -1289,13 +1289,6 @@ static int exynos_tmu_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, data);
mutex_init(&data->lock);

- data->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
- &exynos_sensor_ops);
- if (IS_ERR(data->tzd)) {
- pr_err("thermal: tz: %p ERROR\n", data->tzd);
- return PTR_ERR(data->tzd);
- }
-
/*
* Try enabling the regulator if found
* TODO: Add regulator as an SOC feature, so that regulator enable
@@ -1365,21 +1358,36 @@ static int exynos_tmu_probe(struct platform_device *pdev)
break;
};

+ /*
+ * data->tzd must be registered before calling exynos_tmu_initialize(),
+ * requesting irq and calling exynos_tmu_control().
+ */
+ data->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
+ &exynos_sensor_ops);
+ if (IS_ERR(data->tzd)) {
+ ret = PTR_ERR(data->tzd);
+ dev_err(&pdev->dev, "Failed to register sensor: %d\n", ret);
+ goto err_sclk;
+ }
+
ret = exynos_tmu_initialize(pdev);
if (ret) {
dev_err(&pdev->dev, "Failed to initialize TMU\n");
- goto err_sclk;
+ goto err_thermal;
}

ret = devm_request_irq(&pdev->dev, data->irq, exynos_tmu_irq,
IRQF_TRIGGER_RISING | IRQF_SHARED, dev_name(&pdev->dev), data);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
- goto err_sclk;
+ goto err_thermal;
}

exynos_tmu_control(pdev, true);
return 0;
+
+err_thermal:
+ thermal_zone_of_sensor_unregister(&pdev->dev, data->tzd);
err_sclk:
clk_disable_unprepare(data->sclk);
err_clk:
@@ -1390,7 +1398,6 @@ err_clk_sec:
err_sensor:
if (!IS_ERR_OR_NULL(data->regulator))
regulator_disable(data->regulator);
- thermal_zone_of_sensor_unregister(&pdev->dev, data->tzd);

return ret;
}
--
1.9.1