Commit 07eab46d authored Nov 23, 2005 by Jean Delvare Committed by Linus Torvalds Nov 23, 2005

[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 <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent d0d3cd69

drivers/hwmon/it87.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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);

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