Commit 9a6a1ecd authored by Ian Dall's avatar Ian Dall Committed by Linus Torvalds
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w1: w1 temp: fix negative termperature calculation

Fix regression caused by commit 507e2fba
("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: default avatarIan Dall <ian@beware.dropbear.id.au>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Tested-by: default avatarKarsten Elfenbein <kelfe@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7716fa66
......@@ -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])
......
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