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| author | Jerome Oufella <jerome.oufella@savoirfairelinux.com> | 2010-04-14 16:14:07 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-26 07:47:54 -0700 |
| commit | eeb5f3b99a8ccc55e4ae4b0511a0b05e86d0b78d (patch) | |
| tree | 2a2ecdea78c645025ae1fc7877a78fa1b4f713d4 | |
| parent | fae0017ccf08a2d2ddb5c420793f3591d8ab85cb (diff) | |
| download | lwn-eeb5f3b99a8ccc55e4ae4b0511a0b05e86d0b78d.tar.gz lwn-eeb5f3b99a8ccc55e4ae4b0511a0b05e86d0b78d.zip | |
hwmon: (sht15) Fix sht15_calc_temp interpolation function
commit 328a2c22abd08911e37fa66f1358f829cecd72e9 upstream.
I discovered two issues.
First the previous sht15_calc_temp() loop did not iterate through the
temppoints array since the (data->supply_uV > temppoints[i - 1].vdd)
test is always true in this direction.
Also the two-points linear interpolation function was returning biased
values due to a stray division by 1000 which shouldn't be there.
[JD: Also change the default value for d1 from 0 to something saner.]
Signed-off-by: Jerome Oufella <jerome.oufella@savoirfairelinux.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/hwmon/sht15.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c index 864a371f6eb9..bf41d4e6e5ac 100644 --- a/drivers/hwmon/sht15.c +++ b/drivers/hwmon/sht15.c @@ -302,13 +302,13 @@ error_ret: **/ static inline int sht15_calc_temp(struct sht15_data *data) { - int d1 = 0; + int d1 = temppoints[0].d1; int i; - for (i = 1; i < ARRAY_SIZE(temppoints); i++) + for (i = ARRAY_SIZE(temppoints) - 1; i > 0; i--) /* Find pointer to interpolate */ if (data->supply_uV > temppoints[i - 1].vdd) { - d1 = (data->supply_uV/1000 - temppoints[i - 1].vdd) + d1 = (data->supply_uV - temppoints[i - 1].vdd) * (temppoints[i].d1 - temppoints[i - 1].d1) / (temppoints[i].vdd - temppoints[i - 1].vdd) + temppoints[i - 1].d1; |