Re: [PATCH 2/2] hwmon: (sch5627) Split sch5627_update_device()

[Guenter Roeck <linux@roeck-us.net>]

On Sun, Apr 11, 2021 at 06:42:25PM +0200, W_Armin@gmx.de wrote:
> From: Armin Wolf <W_Armin@gmx.de>
> 
> An error in sch5627_update_device() could cause sch5627_read()
> to fail even if the error did not affect the target sensor type.
> Split sch5627_update_device() to prevent that.
> 
> Tested on a Fujitsu Esprimo P720.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Applied.

Thanks,
Guenter

> ---
>  drivers/hwmon/sch5627.c | 102 +++++++++++++++++++++++++++-------------
>  1 file changed, 69 insertions(+), 33 deletions(-)
> 
> --
> 2.20.1
> 
> diff --git a/drivers/hwmon/sch5627.c b/drivers/hwmon/sch5627.c
> index 023376082ee6..9735f3a81cbb 100644
> --- a/drivers/hwmon/sch5627.c
> +++ b/drivers/hwmon/sch5627.c
> @@ -73,66 +73,96 @@ struct sch5627_data {
> 
>  	struct mutex update_lock;
>  	unsigned long last_battery;	/* In jiffies */
> -	char valid;			/* !=0 if following fields are valid */
> -	unsigned long last_updated;	/* In jiffies */
> +	char temp_valid;		/* !=0 if following fields are valid */
> +	char fan_valid;
> +	char in_valid;
> +	unsigned long temp_last_updated;	/* In jiffies */
> +	unsigned long fan_last_updated;
> +	unsigned long in_last_updated;
>  	u16 temp[SCH5627_NO_TEMPS];
>  	u16 fan[SCH5627_NO_FANS];
>  	u16 in[SCH5627_NO_IN];
>  };
> 
> -static struct sch5627_data *sch5627_update_device(struct device *dev)
> +static int sch5627_update_temp(struct sch5627_data *data)
>  {
> -	struct sch5627_data *data = dev_get_drvdata(dev);
> -	struct sch5627_data *ret = data;
> +	int ret = 0;
>  	int i, val;
> 
>  	mutex_lock(&data->update_lock);
> 
> -	/* Trigger a Vbat voltage measurement every 5 minutes */
> -	if (time_after(jiffies, data->last_battery + 300 * HZ)) {
> -		sch56xx_write_virtual_reg(data->addr, SCH5627_REG_CTRL,
> -					  data->control | 0x10);
> -		data->last_battery = jiffies;
> -	}
> -
>  	/* Cache the values for 1 second */
> -	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
> +	if (time_after(jiffies, data->temp_last_updated + HZ) || !data->temp_valid) {
>  		for (i = 0; i < SCH5627_NO_TEMPS; i++) {
> -			val = sch56xx_read_virtual_reg12(data->addr,
> -				SCH5627_REG_TEMP_MSB[i],
> -				SCH5627_REG_TEMP_LSN[i],
> -				SCH5627_REG_TEMP_HIGH_NIBBLE[i]);
> +			val = sch56xx_read_virtual_reg12(data->addr, SCH5627_REG_TEMP_MSB[i],
> +							 SCH5627_REG_TEMP_LSN[i],
> +							 SCH5627_REG_TEMP_HIGH_NIBBLE[i]);
>  			if (unlikely(val < 0)) {
> -				ret = ERR_PTR(val);
> +				ret = val;
>  				goto abort;
>  			}
>  			data->temp[i] = val;
>  		}
> +		data->temp_last_updated = jiffies;
> +		data->temp_valid = 1;
> +	}
> +abort:
> +	mutex_unlock(&data->update_lock);
> +	return ret;
> +}
> +
> +static int sch5627_update_fan(struct sch5627_data *data)
> +{
> +	int ret = 0;
> +	int i, val;
> 
> +	mutex_lock(&data->update_lock);
> +
> +	/* Cache the values for 1 second */
> +	if (time_after(jiffies, data->fan_last_updated + HZ) || !data->fan_valid) {
>  		for (i = 0; i < SCH5627_NO_FANS; i++) {
> -			val = sch56xx_read_virtual_reg16(data->addr,
> -							 SCH5627_REG_FAN[i]);
> +			val = sch56xx_read_virtual_reg16(data->addr, SCH5627_REG_FAN[i]);
>  			if (unlikely(val < 0)) {
> -				ret = ERR_PTR(val);
> +				ret = val;
>  				goto abort;
>  			}
>  			data->fan[i] = val;
>  		}
> +		data->fan_last_updated = jiffies;
> +		data->fan_valid = 1;
> +	}
> +abort:
> +	mutex_unlock(&data->update_lock);
> +	return ret;
> +}
> +
> +static int sch5627_update_in(struct sch5627_data *data)
> +{
> +	int ret = 0;
> +	int i, val;
> +
> +	mutex_lock(&data->update_lock);
> 
> +	/* Trigger a Vbat voltage measurement every 5 minutes */
> +	if (time_after(jiffies, data->last_battery + 300 * HZ)) {
> +		sch56xx_write_virtual_reg(data->addr, SCH5627_REG_CTRL, data->control | 0x10);
> +		data->last_battery = jiffies;
> +	}
> +
> +	/* Cache the values for 1 second */
> +	if (time_after(jiffies, data->in_last_updated + HZ) || !data->in_valid) {
>  		for (i = 0; i < SCH5627_NO_IN; i++) {
> -			val = sch56xx_read_virtual_reg12(data->addr,
> -				SCH5627_REG_IN_MSB[i],
> -				SCH5627_REG_IN_LSN[i],
> -				SCH5627_REG_IN_HIGH_NIBBLE[i]);
> +			val = sch56xx_read_virtual_reg12(data->addr, SCH5627_REG_IN_MSB[i],
> +							 SCH5627_REG_IN_LSN[i],
> +							 SCH5627_REG_IN_HIGH_NIBBLE[i]);
>  			if (unlikely(val < 0)) {
> -				ret = ERR_PTR(val);
> +				ret = val;
>  				goto abort;
>  			}
>  			data->in[i] = val;
>  		}
> -
> -		data->last_updated = jiffies;
> -		data->valid = 1;
> +		data->in_last_updated = jiffies;
> +		data->in_valid = 1;
>  	}
>  abort:
>  	mutex_unlock(&data->update_lock);
> @@ -200,14 +230,14 @@ static umode_t sch5627_is_visible(const void *drvdata, enum hwmon_sensor_types t
>  static int sch5627_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
>  			long *val)
>  {
> -	struct sch5627_data *data = sch5627_update_device(dev);
> +	struct sch5627_data *data = dev_get_drvdata(dev);
>  	int ret;
> 
> -	if (IS_ERR(data))
> -		return PTR_ERR(data);
> -
>  	switch (type) {
>  	case hwmon_temp:
> +		ret = sch5627_update_temp(data);
> +		if (ret < 0)
> +			return ret;
>  		switch (attr) {
>  		case hwmon_temp_input:
>  			*val = reg_to_temp(data->temp[channel]);
> @@ -226,6 +256,9 @@ static int sch5627_read(struct device *dev, enum hwmon_sensor_types type, u32 at
>  		}
>  		break;
>  	case hwmon_fan:
> +		ret = sch5627_update_fan(data);
> +		if (ret < 0)
> +			return ret;
>  		switch (attr) {
>  		case hwmon_fan_input:
>  			ret = reg_to_rpm(data->fan[channel]);
> @@ -247,6 +280,9 @@ static int sch5627_read(struct device *dev, enum hwmon_sensor_types type, u32 at
>  		}
>  		break;
>  	case hwmon_in:
> +		ret = sch5627_update_in(data);
> +		if (ret < 0)
> +			return ret;
>  		switch (attr) {
>  		case hwmon_in_input:
>  			*val = DIV_ROUND_CLOSEST(data->in[channel] * SCH5627_REG_IN_FACTOR[channel],