Allow override of deviation with absolute minimum RPM

If the devation is less than zero, treat as an absolute minimum RPM value

4 files changed, 23 insertions, 8 deletions

diff --git a/monitor/fan.cpp b/monitor/fan.cpp
index a6af74a..f55ddb3 100644
--- a/monitor/fan.cpp
+++ b/monitor/fan.cpp
@@ -36,7 +36,8 @@ Fan::Fan(Mode mode,
          const FanDefinition& def) :
     _bus(bus),
     _name(std::get<fanNameField>(def)),
-    _deviation(std::get<fanDeviationField>(def)),
+    _deviation((std::get<fanDeviationField>(def) < 0)?abs(std::get<fanDeviationField>(def)):std::get<fanDeviationField>(def)),
+    _deviationIsMinRPM((std::get<fanDeviationField>(def) < 0)?true:false),
     _numSensorFailsForNonFunc(std::get<numSensorFailsForNonfuncField>(def)),
     _trustManager(trust)
 {
@@ -179,12 +180,21 @@ bool Fan::outOfRange(const TachSensor& sensor)
     auto actual = static_cast<uint64_t>(sensor.getInput());
     auto target = getTargetSpeed(sensor);
 
-    uint64_t min = target * (100 - _deviation) / 100;
-    uint64_t max = target * (100 + _deviation) / 100;
-
-    if ((actual < min) || (actual > max))
+    if (_deviationIsMinRPM)
     {
-        return true;
+        if (actual < _deviation)
+        {
+            return true;
+        }
+    }
+    else {
+        uint64_t min = target * (100 - _deviation) / 100;
+        uint64_t max = target * (100 + _deviation) / 100;
+
+        if ((actual < min) || (actual > max))
+        {
+            return true;
+        }
     }
 
     return false;
diff --git a/monitor/fan.hpp b/monitor/fan.hpp
index f22bd9f..cb50c5d 100644
--- a/monitor/fan.hpp
+++ b/monitor/fan.hpp
@@ -187,6 +187,11 @@ class Fan
         const size_t _deviation;
 
         /**
+         * @brief True if deviation indicates minimum absolute RPM
+         */
+        bool _deviationIsMinRPM;
+
+        /**
          * The number of sensors that must be nonfunctional at the
          * same time in order for the fan to be set to nonfunctional
          * in the inventory.
diff --git a/monitor/gen-fan-monitor-defs.py b/monitor/gen-fan-monitor-defs.py
index 1590484..66dbb52 100755
--- a/monitor/gen-fan-monitor-defs.py
+++ b/monitor/gen-fan-monitor-defs.py
@@ -90,7 +90,7 @@ if __name__ == '__main__':
 
     #Do some minor input validation
     for fan in monitor_data.get('fans', {}):
-        if ((fan['deviation'] < 0) or (fan['deviation'] > 100)):
+        if (fan['deviation'] > 100):
             sys.exit("Invalid deviation value " + str(fan['deviation']))
 
     output_file = os.path.join(args.output_dir, "fan_monitor_defs.cpp")
diff --git a/monitor/types.hpp b/monitor/types.hpp
index 795db00..ba6bf13 100644
--- a/monitor/types.hpp
+++ b/monitor/types.hpp
@@ -29,7 +29,7 @@ constexpr auto sensorListField = 4;
 
 using FanDefinition = std::tuple<std::string,
                                  size_t,
-                                 size_t,
+                                 ssize_t,
                                  size_t,
                                  std::vector<SensorDefinition>>;