hwmon: (max6639) Fix FAN_FROM_REG calculation
RPM calculation from tachometer value does not depend on PPR.
Also, do not report negative RPM values.
Signed-off-by: Chris D Schimp <silverchris@gmail.com>
[guenter.roeck@ericsson.com: do not report negative RPM values]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: stable@vger.kernel.org # 3.0+
Acked-by: Roland Stigge <stigge@antcom.de>
diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index e10a092..13e58a1 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -72,8 +72,8 @@
static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
-#define FAN_FROM_REG(val, div, rpm_range) ((val) == 0 ? -1 : \
- (val) == 255 ? 0 : (rpm_ranges[rpm_range] * 30) / ((div + 1) * (val)))
+#define FAN_FROM_REG(val, rpm_range) ((val) == 0 || (val) == 255 ? \
+ 0 : (rpm_ranges[rpm_range] * 30) / (val))
#define TEMP_LIMIT_TO_REG(val) SENSORS_LIMIT((val) / 1000, 0, 255)
/*
@@ -333,7 +333,7 @@
return PTR_ERR(data);
return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
- data->ppr, data->rpm_range));
+ data->rpm_range));
}
static ssize_t show_alarm(struct device *dev,