From 4aaaaf0f279836f06d3b9d0ffeec7a1e1a04ceef Mon Sep 17 00:00:00 2001
From: "Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com>
Date: Mon, 18 Apr 2022 17:07:06 +0800
Subject: [PATCH] hwmon: (f71882fg) Fix negative temperature
Git-commit: 4aaaaf0f279836f06d3b9d0ffeec7a1e1a04ceef
Patch-mainline: v5.18-rc6
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 938a8b9ec70d..6830e029995d 100644
--- a/drivers/hwmon/f71882fg.c
+++ b/drivers/hwmon/f71882fg.c
@@ -1578,8 +1578,9 @@ 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);
}
--
2.35.3