Re: [PATCH v2 3/5] thermal: rockchip: fixes invalid temperature case

[Brian Norris <briannorris@chromium.org>]

Hi Caesar,

On Wed, Nov 23, 2016 at 10:29:32PM +0800, Caesar Wang wrote:
> The temp_to_code function will return 0 when we set the temperature to a
> invalid value (e.g. 61C, 62C, 63C....), that's unpractical. This patch
> will prevent this case happening. That will return the max analog value to
> indicate the temperature is invalid or over table temperature range.
> 
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> ---
> 
> Changes in v2:
> - As Brian commnets that restructure this to pass error codes back to the
>   upper layers.
> - Improve the commit message.
> 
> Changes in v1: None
> 
>  drivers/thermal/rockchip_thermal.c | 41 ++++++++++++++++++++++++++------------
>  1 file changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
> index 766486f..e243e40 100644
> --- a/drivers/thermal/rockchip_thermal.c
> +++ b/drivers/thermal/rockchip_thermal.c
> @@ -120,9 +120,9 @@ struct rockchip_tsadc_chip {
>  	/* Per-sensor methods */
>  	int (*get_temp)(const struct chip_tsadc_table *table,
>  			int chn, void __iomem *reg, int *temp);
> -	void (*set_alarm_temp)(const struct chip_tsadc_table *table,
> +	int (*set_alarm_temp)(const struct chip_tsadc_table *table,
>  			       int chn, void __iomem *reg, int temp);
> -	void (*set_tshut_temp)(const struct chip_tsadc_table *table,
> +	int (*set_tshut_temp)(const struct chip_tsadc_table *table,
>  			       int chn, void __iomem *reg, int temp);
>  	void (*set_tshut_mode)(int chn, void __iomem *reg, enum tshut_mode m);
>  
> @@ -401,17 +401,15 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table,
>  				   int temp)
>  {
>  	int high, low, mid;
> -	u32 error = 0;
> +	u32 error = table->data_mask;
>  
>  	low = 0;
>  	high = table->length - 1;
>  	mid = (high + low) / 2;
>  
>  	/* Return mask code data when the temp is over table range */
> -	if (temp < table->id[low].temp || temp > table->id[high].temp) {
> -		error = table->data_mask;
> +	if (temp < table->id[low].temp || temp > table->id[high].temp)
>  		goto exit;
> -	}
>  
>  	while (low <= high) {
>  		if (temp == table->id[mid].temp)
> @@ -651,7 +649,7 @@ static int rk_tsadcv2_get_temp(const struct chip_tsadc_table *table,
>  	return rk_tsadcv2_code_to_temp(table, val, temp);
>  }
>  
> -static void rk_tsadcv2_alarm_temp(const struct chip_tsadc_table *table,
> +static int rk_tsadcv2_alarm_temp(const struct chip_tsadc_table *table,
>  				  int chn, void __iomem *regs, int temp)
>  {
>  	u32 alarm_value, int_en;
> @@ -659,7 +657,7 @@ static void rk_tsadcv2_alarm_temp(const struct chip_tsadc_table *table,
>  	/* Make sure the value is valid */
>  	alarm_value = rk_tsadcv2_temp_to_code(table, temp);
>  	if (alarm_value == table->data_mask)
> -		return;
> +		return -ERANGE;
>  
>  	writel_relaxed(alarm_value & table->data_mask,
>  		       regs + TSADCV2_COMP_INT(chn));
> @@ -667,9 +665,11 @@ static void rk_tsadcv2_alarm_temp(const struct chip_tsadc_table *table,
>  	int_en = readl_relaxed(regs + TSADCV2_INT_EN);
>  	int_en |= TSADCV2_INT_SRC_EN(chn);
>  	writel_relaxed(int_en, regs + TSADCV2_INT_EN);
> +
> +	return 0;
>  }
>  
> -static void rk_tsadcv2_tshut_temp(const struct chip_tsadc_table *table,
> +static int rk_tsadcv2_tshut_temp(const struct chip_tsadc_table *table,
>  				  int chn, void __iomem *regs, int temp)
>  {
>  	u32 tshut_value, val;
> @@ -677,13 +677,15 @@ static void rk_tsadcv2_tshut_temp(const struct chip_tsadc_table *table,
>  	/* Make sure the value is valid */
>  	tshut_value = rk_tsadcv2_temp_to_code(table, temp);
>  	if (tshut_value == table->data_mask)
> -		return;
> +		return -ERANGE;
>  
>  	writel_relaxed(tshut_value, regs + TSADCV2_COMP_SHUT(chn));
>  
>  	/* TSHUT will be valid */
>  	val = readl_relaxed(regs + TSADCV2_AUTO_CON);
>  	writel_relaxed(val | TSADCV2_AUTO_SRC_EN(chn), regs + TSADCV2_AUTO_CON);
> +
> +	return 0;
>  }
>  
>  static void rk_tsadcv2_tshut_mode(int chn, void __iomem *regs,
> @@ -882,12 +884,17 @@ static int rockchip_thermal_set_trips(void *_sensor, int low, int high)
>  	struct rockchip_thermal_sensor *sensor = _sensor;
>  	struct rockchip_thermal_data *thermal = sensor->thermal;
>  	const struct rockchip_tsadc_chip *tsadc = thermal->chip;
> +	int ret;
>  
>  	dev_dbg(&thermal->pdev->dev, "%s: sensor %d: low: %d, high %d\n",
>  		__func__, sensor->id, low, high);
>  
> -	tsadc->set_alarm_temp(&tsadc->table,
> +	ret = tsadc->set_alarm_temp(&tsadc->table,
>  			      sensor->id, thermal->regs, high);
> +	if (ret)
> +		dev_err(&thermal->pdev->dev,
> +			"%s: disable sensor[%d] alarm temp: %d, ret: %d\n",

You're not necessarily disabling the sensor; you're just not programming
it. If this is the second time setting the trip points (e.g., using
'echo > trip_X_temp') then this just means you've retained the old
value.

Also, I'm not sure you need to print anything here, as the thermal core
prints errors for you. Maybe make this dev_dbg() so it doesn't print by
default?

> +			__func__, sensor->id, high, ret);
>  
>  	return 0;

Oh, but you missed the whole point of returning errors; you need to
propagate 'ret' here! i.e.:

	return ret;

Brian

>  }
> @@ -985,8 +992,12 @@ rockchip_thermal_register_sensor(struct platform_device *pdev,
>  	int error;
>  
>  	tsadc->set_tshut_mode(id, thermal->regs, thermal->tshut_mode);
> -	tsadc->set_tshut_temp(&tsadc->table, id, thermal->regs,
> +
> +	error = tsadc->set_tshut_temp(&tsadc->table, id, thermal->regs,
>  			      thermal->tshut_temp);
> +	if (error)
> +		dev_err(&pdev->dev, "%s: invalid tshut=%d, error=%d\n",
> +			__func__, thermal->tshut_temp, error);
>  
>  	sensor->thermal = thermal;
>  	sensor->id = id;
> @@ -1199,9 +1210,13 @@ static int __maybe_unused rockchip_thermal_resume(struct device *dev)
>  
>  		thermal->chip->set_tshut_mode(id, thermal->regs,
>  					      thermal->tshut_mode);
> -		thermal->chip->set_tshut_temp(&thermal->chip->table,
> +
> +		error = thermal->chip->set_tshut_temp(&thermal->chip->table,
>  					      id, thermal->regs,
>  					      thermal->tshut_temp);
> +		if (error)
> +			dev_err(&pdev->dev, "%s: invalid tshut=%d, error=%d\n",
> +				__func__, thermal->tshut_temp, error);
>  	}
>  
>  	thermal->chip->control(thermal->regs, true);
> -- 
> 2.7.4
>