From: Jean Delvare Date: Wed, 23 Nov 2005 23:44:31 +0000 (-0800) Subject: [PATCH] hwmon: Fix missing it87 fan div init X-Git-Tag: firefly_0821_release~39800 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=07eab46db7f78b2ed49bc9e41eda80695f93886f;p=firefly-linux-kernel-4.4.55.git [PATCH] hwmon: Fix missing it87 fan div init Fix a bug where setting the low fan speed limits will not work if no data was ever read through the sysfs interface and the fan clock dividers have not been explicitely set yet either. The reason is that data->fan_div[nr] may currently be used before it is initialized from the chip register values. The fix is to explicitely initialize data->fan_div[nr] before using it. Bug reported, and fix tested, by Nicolas Mailhot. Signed-off-by: Jean Delvare Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c index 6c41e25e670b..a61f5d00f10a 100644 --- a/drivers/hwmon/it87.c +++ b/drivers/hwmon/it87.c @@ -522,8 +522,15 @@ static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr, struct i2c_client *client = to_i2c_client(dev); struct it87_data *data = i2c_get_clientdata(client); int val = simple_strtol(buf, NULL, 10); + u8 reg = it87_read_value(client, IT87_REG_FAN_DIV); down(&data->update_lock); + switch (nr) { + case 0: data->fan_div[nr] = reg & 0x07; break; + case 1: data->fan_div[nr] = (reg >> 3) & 0x07; break; + case 2: data->fan_div[nr] = (reg & 0x40) ? 3 : 1; break; + } + data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr])); it87_write_value(client, IT87_REG_FAN_MIN(nr), data->fan_min[nr]); up(&data->update_lock);