From: Jean Delvare <khali@xxxxxxxxxxxx> commit 33a7ab91d509fa33b4bcd3ce0038cc80298050da upstream. The W83L786NG stores the fan speed on 4 bits while the sysfs interface uses a 0-255 range. Thus the driver should scale the user input down to map it to the device range, and scale up the value read from the device before presenting it to the user. The reserved register nibble should be left unchanged. Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> --- The upstream patch failed to apply to the 3.4 kernel tree, here's a backport. drivers/hwmon/w83l786ng.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- linux-3.4.orig/drivers/hwmon/w83l786ng.c 2013-12-19 08:17:40.771102727 +0100 +++ linux-3.4/drivers/hwmon/w83l786ng.c 2013-12-19 08:42:59.145694049 +0100 @@ -481,9 +481,11 @@ store_pwm(struct device *dev, struct dev if (err) return err; val = SENSORS_LIMIT(val, 0, 255); + val = DIV_ROUND_CLOSEST(val, 0x11); mutex_lock(&data->update_lock); - data->pwm[nr] = val; + data->pwm[nr] = val * 0x11; + val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0; w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val); mutex_unlock(&data->update_lock); return count; @@ -782,8 +784,9 @@ static struct w83l786ng_data *w83l786ng_ ? 0 : 1; data->pwm_enable[i] = ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1; - data->pwm[i] = w83l786ng_read_value(client, - W83L786NG_REG_PWM[i]); + data->pwm[i] = + (w83l786ng_read_value(client, W83L786NG_REG_PWM[i]) + & 0x0f) * 0x11; } -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html