All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jean Delvare <khali@linux-fr.org>
To: lm-sensors@vger.kernel.org
Subject: [lm-sensors] [PATCH] hwmon: (sht15) Fix sht15_calc_temp
Date: Thu, 01 Apr 2010 15:02:39 +0000	[thread overview]
Message-ID: <20100401170239.3c745577@hyperion.delvare> (raw)

From: Jerome Oufella <jerome.oufella@savoirfairelinux.com>

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>
Cc: stable@kernel.org
---
 drivers/hwmon/sht15.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-2.6.34-rc3.orig/drivers/hwmon/sht15.c	2010-04-01 16:24:33.000000000 +0200
+++ linux-2.6.34-rc3/drivers/hwmon/sht15.c	2010-04-01 16:49:45.000000000 +0200
@@ -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;


-- 
Jean Delvare

_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

             reply	other threads:[~2010-04-01 15:02 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-01 15:02 Jean Delvare [this message]
  -- strict thread matches above, loose matches on Subject: below --
2010-03-26 21:30 [lm-sensors] [PATCH] hwmon: sht15: Fix sht15_calc_temp Jerome Oufella
2010-03-29 16:23 ` Jerome Oufella
2010-03-29 18:42 ` Jonathan Cameron
2010-03-29 19:58 ` Jerome Oufella
2010-03-30 11:36 ` Jonathan Cameron
2010-03-30 14:00 ` Jerome Oufella
2010-03-30 14:00 ` Jerome Oufella
2010-04-01 12:01 ` Jean Delvare
2010-04-01 12:54 ` Jerome Oufella
2010-04-01 13:49   ` Jonathan Cameron

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20100401170239.3c745577@hyperion.delvare \
    --to=khali@linux-fr.org \
    --cc=lm-sensors@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.