hwmon: (k10temp) Only apply temperature offset if result is positive

Commit Message

Guenter Roeck Feb. 8, 2018, 1:57 a.m. UTC

A user reports a really bad temperature on Ryzen 1950X.

k10temp-pci-00cb
Adapter: PCI adapter
temp1: +4294948.3°C (high = +70.0°C)

This will happen if the temperature reported by the chip is lower than
the offset temperature. If that happens, let's report a temperature
of 0 degrees C.

Fixes: 1b50b776355f ("hwmon: (k10temp) Add support for temperature offsets")
Signed-off-by: Guenter Roeck <[e-mail]>
---
 drivers/hwmon/k10temp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
index 06b4e1c78bd8..4c6594a4661d 100644
--- a/drivers/hwmon/k10temp.c
+++ b/drivers/hwmon/k10temp.c
@@ -129,7 +129,10 @@  static ssize_t temp1_input_show(struct device *dev,
 
 	data->read_tempreg(data->pdev, &regval);
 	temp = (regval >> 21) * 125;
-	temp -= data->temp_offset;
+	if (temp > data->temp_offset)
+		temp -= data->temp_offset;
+	else
+		temp = 0;
 
 	return sprintf(buf, "%u\n", temp);
 }