| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 18/43] hwmon: (f71882fg) Fix negative temperature | Date | Mon, 16 May 2022 21:36:29 +0200 |
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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.com 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 d09deb409de7..3336ff9e306b 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); } -- 2.35.1
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