2014-04-03 06:11:44

by Lan Tianyu

[permalink] [raw]
Subject: [PATCH] Thermal/int3403: Fix thermal hysteresis unit conversion

Thermal hysteresis represents a temperature difference.
But the original code treats it as a temperature value,
Convert it from tenths of degree Kelvin to Milli-Celsius
by deducing 273200. This is not right.

Kelvin and Celsius have same degree size. From temperature
difference view, the conversion between tenths of degree
Kelvin unit and Milli-Celsius unit is just to multiply 100.

Signed-off-by: Lan Tianyu <[email protected]>
Acked-by: Srinivas Pandruvada <[email protected]>
---
drivers/thermal/int3403_thermal.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/int3403_thermal.c b/drivers/thermal/int3403_thermal.c
index 1301681..e93f025 100644
--- a/drivers/thermal/int3403_thermal.c
+++ b/drivers/thermal/int3403_thermal.c
@@ -62,7 +62,13 @@ static int sys_get_trip_hyst(struct thermal_zone_device *tzone,
if (ACPI_FAILURE(status))
return -EIO;

- *temp = DECI_KELVIN_TO_MILLI_CELSIUS(hyst, KELVIN_OFFSET);
+ /*
+ * Thermal hysteresis represents a temperature difference.
+ * Kelvin and Celsius have same degree size. So the
+ * conversion here between tenths of degree Kelvin unit
+ * and Milli-Celsius unit is just to multiply 100.
+ */
+ *temp = hyst * 100;

return 0;
}
--
1.8.4.rc0.1.g8f6a3e5.dirty