]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
w1: w1 temp calculation overflow fix
authorIan Dall <ian@beware.dropbear.id.au>
Wed, 11 Feb 2009 21:04:46 +0000 (13:04 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Feb 2009 22:25:37 +0000 (14:25 -0800)
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12646

When the temperature exceeds 32767 milli-degrees the temperature overflows
to -32768 millidegrees.  These are bothe well within the -55 - +125 degree
range for the sensor.

Fix overflow in left-shift of a u8.

Signed-off-by: Ian Dall <ian@beware.dropbear.id.au>
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/slaves/w1_therm.c

index 2c8dff9f77da13396b0d02207e15d486ddbd5d4e..1ed3d554e3728a1f7b6fb51501b1df52d26f514d 100644 (file)
@@ -115,7 +115,7 @@ static struct w1_therm_family_converter w1_therm_families[] = {
 
 static inline int w1_DS18B20_convert_temp(u8 rom[9])
 {
-       s16 t = (rom[1] << 8) | rom[0];
+       int t = ((s16)rom[1] << 8) | rom[0];
        t = t*1000/16;
        return t;
 }