From: "Ji-Ze Hong (Peter Hong)" hpeter@gmail.com
[ Upstream commit 4aaaaf0f279836f06d3b9d0ffeec7a1e1a04ceef ]
All temperature of Fintek superio hwmonitor that using 1-byte reg will use 2's complement.
In show_temp() temp = data->temp[nr] * 1000;
When data->temp[nr] read as 255, it indicate -1C, but this code will report 255C to userspace. It'll be ok when change to: temp = ((s8)data->temp[nr]) * 1000;
Signed-off-by: Ji-Ze Hong (Peter Hong) hpeter+linux_kernel@gmail.com Link: https://lore.kernel.org/r/20220418090706.6339-1-hpeter+linux_kernel@gmail.co... Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/f71882fg.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/f71882fg.c b/drivers/hwmon/f71882fg.c index 4dec793fd07d..94b35723ee7a 100644 --- a/drivers/hwmon/f71882fg.c +++ b/drivers/hwmon/f71882fg.c @@ -1577,8 +1577,9 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, temp *= 125; if (sign) temp -= 128000; - } else - temp = data->temp[nr] * 1000; + } else { + temp = ((s8)data->temp[nr]) * 1000; + }
return sprintf(buf, "%d\n", temp); }