From: Jean Delvare <khali@linux-fr.org>
Date: Fri, 5 Mar 2010 21:17:25 +0000 (+0100)
Subject: hwmon: (tmp421) Fix temperature conversions
X-Git-Tag: v2.6.34-rc1~25^2~2
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=a44908d742a577fb5ccb9a8c082326d4cea234c2;p=net-next-2.6.git

hwmon: (tmp421) Fix temperature conversions

The low bits of temperature registers are status bits, they must be
masked out before converting the register values to temperatures.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Andre Prendel <andre.prendel@gmx.de>
Cc: stable@kernel.org
---

diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index a97e299b233..bb9760d7e8b 100644
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -80,14 +80,16 @@ struct tmp421_data {
 
 static int temp_from_s16(s16 reg)
 {
-	int temp = reg;
+	/* Mask out status bits */
+	int temp = reg & ~0xf;
 
 	return (temp * 1000 + 128) / 256;
 }
 
 static int temp_from_u16(u16 reg)
 {
-	int temp = reg;
+	/* Mask out status bits */
+	int temp = reg & ~0xf;
 
 	/* Add offset for extended temperature range. */
 	temp -= 64 * 256;