Commit 7133e56f authored by Jean Delvare's avatar Jean Delvare Committed by Mark M. Hoffman
Browse files

hwmon: (lm85) Don't write back cached values 



In set_pwm_auto_pwm_minctl, we write cached register bits back to the
chip. This is a bad idea as we have no guarantee that the cache is
up-to-date. Better read a fresh register value from the chip, it's
safer and in fact it is also more simple.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Acked-by: Juerg Haefliger <juergh at gmail.com>
Signed-off-by: default avatarMark M. Hoffman <mhoffman@lightlink.com>
parent dd1ac538

drivers/hwmon/lm85.c

+6 −9
Original line number Diff line number Diff line
@@ -308,10 +308,8 @@ struct lm85_data { 
	u8 pwm[3];		/* Register value */

	u8 temp_ext[3];		/* Decoded values */

	u8 in_ext[8];		/* Decoded values */

	u8 smooth[1];		/* Register encoding */

	u8 vid;			/* Register value */

	u8 vrm;			/* VRM version */

	u8 syncpwm3;		/* Saved PWM3 for TACH 2,3,4 config */

	u32 alarms;		/* Register encoding, combined */

	struct lm85_autofan autofan[3];

	struct lm85_zone zone[3];
@@ -756,14 +754,15 @@ static ssize_t set_pwm_auto_pwm_minctl(struct device *dev, 
	struct i2c_client *client = to_i2c_client(dev);

	struct lm85_data *data = i2c_get_clientdata(client);

	long val = simple_strtol(buf, NULL, 10);

	u8 tmp;



	mutex_lock(&data->update_lock);

	data->autofan[nr].min_off = val;

	lm85_write_value(client, LM85_REG_AFAN_SPIKE1, data->smooth[0]

		| data->syncpwm3

		| (data->autofan[0].min_off ? 0x20 : 0)

		| (data->autofan[1].min_off ? 0x40 : 0)

		| (data->autofan[2].min_off ? 0x80 : 0));

	tmp = lm85_read_value(client, LM85_REG_AFAN_SPIKE1);

	tmp &= ~(0x20 << nr);

	if (data->autofan[nr].min_off)

		tmp |= 0x20 << nr;

	lm85_write_value(client, LM85_REG_AFAN_SPIKE1, tmp);

	mutex_unlock(&data->update_lock);

	return count;

}
@@ -1531,8 +1530,6 @@ static struct lm85_data *lm85_update_device(struct device *dev) 
		}



		i = lm85_read_value(client, LM85_REG_AFAN_SPIKE1);

		data->smooth[0] = i & 0x0f;

		data->syncpwm3 = i & 0x10;  /* Save PWM3 config */

		data->autofan[0].min_off = (i & 0x20) != 0;

		data->autofan[1].min_off = (i & 0x40) != 0;

		data->autofan[2].min_off = (i & 0x80) != 0;

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