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authorIan Dall <ian@beware.dropbear.id.au>2010-04-23 13:17:53 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-04-24 11:31:25 -0700
commit9a6a1ecd9e9b5d046a236da2f7eb6b6812f04229 (patch)
tree8426a3850a3742d09f3a44188a35725e7f0f5cf1
parent7716fa66034c408b0f59e8b9c62f793befa5b338 (diff)
w1: w1 temp: fix negative termperature calculation
Fix regression caused by commit 507e2fbaaacb6f164b4125b87c5002f95143174b ("w1: w1 temp calculation overflow fix") whereby negative temperatures for the DS18B20 are not converted properly. When the temperature exceeds 32767 milli-degrees the temperature overflows to -32768 millidegrees. These are both well within the -55 - +125 degree range for the sensor. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=12646 Signed-of-by: Ian Dall <ian@beware.dropbear.id.au> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Tested-by: Karsten Elfenbein <kelfe@gmx.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/w1/slaves/w1_therm.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 1ed3d554e37..17726a05a0a 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -115,9 +115,8 @@ static struct w1_therm_family_converter w1_therm_families[] = {
static inline int w1_DS18B20_convert_temp(u8 rom[9])
{
- int t = ((s16)rom[1] << 8) | rom[0];
- t = t*1000/16;
- return t;
+ s16 t = le16_to_cpup((__le16 *)rom);
+ return t*1000/16;
}
static inline int w1_DS18S20_convert_temp(u8 rom[9])