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: v2.6.32.10~52
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=bc6fb9e8ba0e5ec6641527b2cfdf170e332f6a5e;p=karo-tx-linux.git

hwmon: (tmp421) Fix temperature conversions

commit a44908d742a577fb5ccb9a8c082326d4cea234c2 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index 20924343431b..7b974c803354 100644
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -81,14 +81,16 @@ 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;