diff options
| author |   David Fries <david@fries.net> | 2008-01-22 03:31:37 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-01-22 09:17:48 -0800 |
| commit | 941ed3b53086697eac7449f3ab5d2c5ab3259de2 (patch) | |
| tree | cd0192ab9a6ab906edc59be1ccf92df49b206c9a /drivers | |
| parent | Makefile: Change typoed 'behavour' to 'behaviour' (diff) | |
| download | linux-dev-941ed3b53086697eac7449f3ab5d2c5ab3259de2.tar.xz linux-dev-941ed3b53086697eac7449f3ab5d2c5ab3259de2.zip | |
W1: w1_therm.c ds18b20 decode freezing temperatures correctly
Correct the decoding of negative C temperatures. The code did a binary OR
of two bytes to make a 16 bit value, but assignd it to an integer. This
caused the value to not be sign extended and to loose that it was a
negative number in the assignment.
Before the patch (in my freezer),
w1_slave
ed fe 4b 46 7f ff 03 10 e4 : crc=e4 YES
ed fe 4b 46 7f ff 03 10 e4 t=4078
With the patch,
e3 fe 4b 46 7f ff 0d 10 81 : crc=81 YES
e3 fe 4b 46 7f ff 0d 10 81 t=-17
Signed-off-by: David Fries <david@fries.net>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/w1/slaves/w1_therm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index 4318935678c5..feed89e733e4 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -112,7 +112,7 @@ static struct w1_therm_family_converter w1_therm_families[] = { static inline int w1_DS18B20_convert_temp(u8 rom[9]) { - int t = (rom[1] << 8) | rom[0]; + s16 t = (rom[1] << 8) | rom[0]; t /= 16; return t; } |