From: Armin Wolf <W_Armin@xxxxxx>
[ Upstream commit 0331b1b0ba65376ecf1c69414aa7696fef0930cb ]
After using the built-in UEFI hardware diagnostics to compare
the measured battery temperature, i noticed that the temperature
is actually expressed in tenth degree kelvin, similar to the
SBS-Data standard. For example, a value of 2992 is displayed as
26 degrees celsius.
Fix the scaling so that the correct values are being displayed.
Tested on a Dell Inspiron 3505.
Fixes: a77272c16041 ("platform/x86: dell: Add new dell-wmi-ddv driver")
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Link: https://lore.kernel.org/r/20230218115318.20662-2-W_Armin@xxxxxx
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/platform/x86/dell/dell-wmi-ddv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
index f99c4cb686fdc..96fede24877f3 100644
--- a/drivers/platform/x86/dell/dell-wmi-ddv.c
+++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
@@ -14,7 +14,6 @@
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kstrtox.h>
-#include <linux/math.h>
#include <linux/module.h>
#include <linux/limits.h>
#include <linux/power_supply.h>
@@ -192,7 +191,8 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char
if (ret < 0)
return ret;
- return sysfs_emit(buf, "%d\n", DIV_ROUND_CLOSEST(value, 10));
+ /* Use 2731 instead of 2731.5 to avoid unnecessary rounding */
+ return sysfs_emit(buf, "%d\n", value - 2731);
}
static ssize_t eppid_show(struct device *dev, struct device_attribute *attr, char *buf)
--
2.39.2
