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authorGuenter Roeck <linux@roeck-us.net>2016-12-04 18:15:25 -0800
committerGuenter Roeck <linux@roeck-us.net>2016-12-12 11:32:34 -0800
commitc0d04e9112ad59d73f23f3b0f6726c5e798dfcbf (patch)
tree3b425cece8455b70bdb0e3641c4084ba2d863c3a /drivers/hwmon
parent64bd708ae0edced5eee764c2321b280bc1e16550 (diff)
hwmon: (nct7802) Fix overflows seen when writing into limit attributes
Fix overflows seen when writing voltage and temperature limit attributes. The value passed to DIV_ROUND_CLOSEST() needs to be clamped, and the value parameter passed to nct7802_write_fan_min() is an unsigned long. Also, writing values larger than 2700000 into a fan limit attribute results in writing 0 into the chip's limit registers. The exact behavior when writing this value is unspecified. For consistency, report a limit of 1350000 if the chip register reads 0. This may be wrong, and the chip behavior should be verified with the actual chip, but it is better than reporting a value of 0 (which, when written, results in writing a value of 0x1fff into the chip register). Fixes: 3434f3783580 ("hwmon: Driver for Nuvoton NCT7802Y") Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/nct7802.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c
index 3ce33d244cc0..12b94b094c0d 100644
--- a/drivers/hwmon/nct7802.c
+++ b/drivers/hwmon/nct7802.c
@@ -259,13 +259,15 @@ static int nct7802_read_fan_min(struct nct7802_data *data, u8 reg_fan_low,
ret = 0;
else if (ret)
ret = DIV_ROUND_CLOSEST(1350000U, ret);
+ else
+ ret = 1350000U;
abort:
mutex_unlock(&data->access_lock);
return ret;
}
static int nct7802_write_fan_min(struct nct7802_data *data, u8 reg_fan_low,
- u8 reg_fan_high, unsigned int limit)
+ u8 reg_fan_high, unsigned long limit)
{
int err;
@@ -326,8 +328,8 @@ static int nct7802_write_voltage(struct nct7802_data *data, int nr, int index,
int shift = 8 - REG_VOLTAGE_LIMIT_MSB_SHIFT[index - 1][nr];
int err;
+ voltage = clamp_val(voltage, 0, 0x3ff * nct7802_vmul[nr]);
voltage = DIV_ROUND_CLOSEST(voltage, nct7802_vmul[nr]);
- voltage = clamp_val(voltage, 0, 0x3ff);
mutex_lock(&data->access_lock);
err = regmap_write(data->regmap,
@@ -402,7 +404,7 @@ static ssize_t store_temp(struct device *dev, struct device_attribute *attr,
if (err < 0)
return err;
- val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
+ val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
err = regmap_write(data->regmap, nr, val & 0xff);
return err ? : count;