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| author | Guenter Roeck <linux@roeck-us.net> | 2016-12-05 05:15:25 +0300 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2016-12-12 22:32:34 +0300 |
| commit | c0d04e9112ad59d73f23f3b0f6726c5e798dfcbf (patch) | |
| tree | 3b425cece8455b70bdb0e3641c4084ba2d863c3a /drivers/hwmon | |
| parent | 64bd708ae0edced5eee764c2321b280bc1e16550 (diff) | |
| download | linux-c0d04e9112ad59d73f23f3b0f6726c5e798dfcbf.tar.xz | |
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.c | 8 |
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; |