From 7133e56f29030b13601d3399e20050053e560860 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sat, 12 Apr 2008 19:56:35 +0200 Subject: [PATCH] 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: Jean Delvare Acked-by: Juerg Haefliger Signed-off-by: Mark M. Hoffman --- drivers/hwmon/lm85.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c index 0d31435b333..645b98c187c 100644 --- a/drivers/hwmon/lm85.c +++ b/drivers/hwmon/lm85.c @@ -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; -- 2.41.0