hwmon/w83627ehf: Fix timing issues

* I have experimental evidence that the W83627EHG needs more than 1
second to refresh all the measured values. Increase the caching time to
1.5 second.
* When changing a fan clock divider, the corresponding fan speed
measurement register is no longer valid, until the next time the chip
will refresh it. One way to fix this is to pretend that the cache is
still valid for one more period (1.5 second.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
index e615b8378fc3313a7f4f79a8121ee6e12d07b2e5..0c2d929cf573dde749c742a2e103e9ada0e2e104 100644 (file)
--- a/drivers/hwmon/w83627ehf.c
+++ b/drivers/hwmon/w83627ehf.c
@@ -421,7 +421,7 @@ static struct w83627ehf_data *w83627ehf_update_device(struct device *dev)
 
        mutex_lock(&data->update_lock);
 
-       if (time_after(jiffies, data->last_updated + HZ)
+       if (time_after(jiffies, data->last_updated + HZ + HZ/2)
         || !data->valid) {
                /* Fan clock dividers */
                i = w83627ehf_read_value(data, W83627EHF_REG_FANDIV1);
@@ -727,6 +727,8 @@ store_fan_min(struct device *dev, struct device_attribute *attr,
                        div_from_reg(new_div));
                data->fan_div[nr] = new_div;
                w83627ehf_write_fan_div(data, nr);
+               /* Give the chip time to sample a new speed value */
+               data->last_updated = jiffies;
        }
        w83627ehf_write_value(data, W83627EHF_REG_FAN_MIN[nr],
                              data->fan_min[nr]);