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authorIan Dall <ian@beware.dropbear.id.au>2010-04-23 13:17:53 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-12 14:57:00 -0700
commit4268c2cbe019db682f9d493eb728c942d1cc2fb8 (patch)
tree8747f5c0c2b0b38a0b7c7a183a7258723463cf62 /drivers
parent00752c01d2ef9c60e043ef01f4af987846815dae (diff)
w1: w1 temp: fix negative termperature calculation
commit 9a6a1ecd9e9b5d046a236da2f7eb6b6812f04229 upstream. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-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 1ed3d554e372..17726a05a0a6 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])