[PATCH v2 1/3] hwmon: (lm87) Propagate sysfs write errors
From: Baek Kyu, Kim
Date: Thu Oct 29 2026 - 12:40:45 EST
Check the I2C result before updating cached values for writable
attributes. Handle both writes in fan divider changes separately so a
failed second write does not hide the first one.
Signed-off-by: Baek Kyu, Kim <pocj8ur4in@xxxxxxxxx>
---
drivers/hwmon/lm87.c | 96 ++++++++++++++++++++++++++++----------------
1 file changed, 61 insertions(+), 35 deletions(-)
diff --git a/drivers/hwmon/lm87.c b/drivers/hwmon/lm87.c
index c09074f44708..c118a7ff718b 100644
--- a/drivers/hwmon/lm87.c
+++ b/drivers/hwmon/lm87.c
@@ -305,6 +305,7 @@ static ssize_t in_min_store(struct device *dev, struct device_attribute *attr,
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
int nr = to_sensor_dev_attr(attr)->index;
+ u8 reg;
long val;
int err;
@@ -312,12 +313,14 @@ static ssize_t in_min_store(struct device *dev, struct device_attribute *attr,
if (err)
return err;
+ reg = IN_TO_REG(val, data->in_scale[nr]);
mutex_lock(&data->update_lock);
- data->in_min[nr] = IN_TO_REG(val, data->in_scale[nr]);
- lm87_write_value(client, nr < 6 ? LM87_REG_IN_MIN(nr) :
- LM87_REG_AIN_MIN(nr - 6), data->in_min[nr]);
+ err = lm87_write_value(client, nr < 6 ? LM87_REG_IN_MIN(nr) :
+ LM87_REG_AIN_MIN(nr - 6), reg);
+ if (!err)
+ data->in_min[nr] = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static ssize_t in_max_store(struct device *dev, struct device_attribute *attr,
@@ -326,6 +329,7 @@ static ssize_t in_max_store(struct device *dev, struct device_attribute *attr,
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
int nr = to_sensor_dev_attr(attr)->index;
+ u8 reg;
long val;
int err;
@@ -333,12 +337,14 @@ static ssize_t in_max_store(struct device *dev, struct device_attribute *attr,
if (err)
return err;
+ reg = IN_TO_REG(val, data->in_scale[nr]);
mutex_lock(&data->update_lock);
- data->in_max[nr] = IN_TO_REG(val, data->in_scale[nr]);
- lm87_write_value(client, nr < 6 ? LM87_REG_IN_MAX(nr) :
- LM87_REG_AIN_MAX(nr - 6), data->in_max[nr]);
+ err = lm87_write_value(client, nr < 6 ? LM87_REG_IN_MAX(nr) :
+ LM87_REG_AIN_MAX(nr - 6), reg);
+ if (!err)
+ data->in_max[nr] = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static SENSOR_DEVICE_ATTR_RO(in0_input, in_input, 0);
@@ -402,6 +408,7 @@ static ssize_t temp_low_store(struct device *dev,
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
int nr = to_sensor_dev_attr(attr)->index;
+ u8 reg;
long val;
int err;
@@ -409,11 +416,13 @@ static ssize_t temp_low_store(struct device *dev,
if (err)
return err;
+ reg = TEMP_TO_REG(val);
mutex_lock(&data->update_lock);
- data->temp_low[nr] = TEMP_TO_REG(val);
- lm87_write_value(client, LM87_REG_TEMP_LOW[nr], data->temp_low[nr]);
+ err = lm87_write_value(client, LM87_REG_TEMP_LOW[nr], reg);
+ if (!err)
+ data->temp_low[nr] = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static ssize_t temp_high_store(struct device *dev,
@@ -423,6 +432,7 @@ static ssize_t temp_high_store(struct device *dev,
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
int nr = to_sensor_dev_attr(attr)->index;
+ u8 reg;
long val;
int err;
@@ -430,11 +440,13 @@ static ssize_t temp_high_store(struct device *dev,
if (err)
return err;
+ reg = TEMP_TO_REG(val);
mutex_lock(&data->update_lock);
- data->temp_high[nr] = TEMP_TO_REG(val);
- lm87_write_value(client, LM87_REG_TEMP_HIGH[nr], data->temp_high[nr]);
+ err = lm87_write_value(client, LM87_REG_TEMP_HIGH[nr], reg);
+ if (!err)
+ data->temp_high[nr] = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
@@ -502,6 +514,7 @@ static ssize_t fan_min_store(struct device *dev,
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
int nr = to_sensor_dev_attr(attr)->index;
+ u8 reg;
long val;
int err;
@@ -510,11 +523,12 @@ static ssize_t fan_min_store(struct device *dev,
return err;
mutex_lock(&data->update_lock);
- data->fan_min[nr] = FAN_TO_REG(val,
- FAN_DIV_FROM_REG(data->fan_div[nr]));
- lm87_write_value(client, LM87_REG_FAN_MIN(nr), data->fan_min[nr]);
+ reg = FAN_TO_REG(val, FAN_DIV_FROM_REG(data->fan_div[nr]));
+ err = lm87_write_value(client, LM87_REG_FAN_MIN(nr), reg);
+ if (!err)
+ data->fan_min[nr] = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
/*
@@ -533,7 +547,7 @@ static ssize_t fan_div_store(struct device *dev,
long val;
int err;
unsigned long min;
- u8 reg;
+ u8 reg, div, fan_min;
err = kstrtol(buf, 10, &val);
if (err)
@@ -545,39 +559,47 @@ static ssize_t fan_div_store(struct device *dev,
switch (val) {
case 1:
- data->fan_div[nr] = 0;
+ div = 0;
break;
case 2:
- data->fan_div[nr] = 1;
+ div = 1;
break;
case 4:
- data->fan_div[nr] = 2;
+ div = 2;
break;
case 8:
- data->fan_div[nr] = 3;
+ div = 3;
break;
default:
mutex_unlock(&data->update_lock);
return -EINVAL;
}
- reg = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
+ err = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
+ if (err < 0)
+ goto out;
+ reg = err;
switch (nr) {
case 0:
- reg = (reg & 0xCF) | (data->fan_div[0] << 4);
+ reg = (reg & 0xCF) | (div << 4);
break;
case 1:
- reg = (reg & 0x3F) | (data->fan_div[1] << 6);
+ reg = (reg & 0x3F) | (div << 6);
break;
}
- lm87_write_value(client, LM87_REG_VID_FAN_DIV, reg);
-
- data->fan_min[nr] = FAN_TO_REG(min, val);
- lm87_write_value(client, LM87_REG_FAN_MIN(nr),
- data->fan_min[nr]);
+ err = lm87_write_value(client, LM87_REG_VID_FAN_DIV, reg);
+ if (err < 0)
+ goto out;
+ data->fan_div[nr] = div;
+
+ fan_min = FAN_TO_REG(min, val);
+ err = lm87_write_value(client, LM87_REG_FAN_MIN(nr), fan_min);
+ if (!err)
+ data->fan_min[nr] = fan_min;
+out:
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
@@ -640,6 +662,7 @@ static ssize_t aout_output_store(struct device *dev,
{
struct i2c_client *client = dev_get_drvdata(dev);
struct lm87_data *data = i2c_get_clientdata(client);
+ u8 reg;
long val;
int err;
@@ -647,11 +670,14 @@ static ssize_t aout_output_store(struct device *dev,
if (err)
return err;
+ reg = AOUT_TO_REG(val);
+
mutex_lock(&data->update_lock);
- data->aout = AOUT_TO_REG(val);
- lm87_write_value(client, LM87_REG_AOUT, data->aout);
+ err = lm87_write_value(client, LM87_REG_AOUT, reg);
+ if (!err)
+ data->aout = reg;
mutex_unlock(&data->update_lock);
- return count;
+ return err < 0 ? err : count;
}
static DEVICE_ATTR_RW(aout_output);
--
2.55.0