PSUSensor.cpp - Removed PSU

[Mark Woodward]

Here is a diff

diff --git a/src/PSUSensor.cpp b/src/PSUSensor.cpp
index e454c74..4072e07 100644
--- a/src/PSUSensor.cpp
+++ b/src/PSUSensor.cpp
@@ -133,6 +133,31 @@ void PSUSensor::deactivate()
     i2cDevice = nullptr;
     path = "";
 }
+bool PSUSensor::readStatusClearValue(bool success)
+{
+    bool result = false;
+    if(success)
+    {
+        lastClear = 0;
+    }
+    else
+    {
+        unsigned int now = (unsigned int) time(0);
+        if(lastClear == 0)
+        {
+            lastClear = now;
+        }
+        else
+        {
+            if((now - lastClear) > timeout_before_clear)
+            {
+                result = true;
+                lastClear = 0;
+            }
+        }
+    }
+    return result;
+}

 void PSUSensor::setupRead(void)
 {
@@ -214,12 +239,19 @@ void PSUSensor::handleResponse(const
boost::system::error_code& err,
     {
         if (readingStateGood())
         {
-            std::cerr << name << " read failed\n";
+            std::cerr << name << " read failed:" << err << "\n";
+            if(readStatusClearValue(false))
+            {
+                std::cerr << name << " clearing value" << "\n";
+                updateValue(0 + sensorOffset);
+            }
         }
         restartRead();
         return;
     }

+    readStatusClearValue(true);
+
     // null terminate the string so we don't walk off the end
     std::array<char, 128>& bufferRef = *buffer;
     bufferRef[bytesRead] = '\0';
diff --git a/src/PSUSensor.hpp b/src/PSUSensor.hpp
index b49235f..a7ee95d 100644
--- a/src/PSUSensor.hpp
+++ b/src/PSUSensor.hpp
@@ -61,6 +61,16 @@ class PSUSensor : public Sensor, public
std::enable_shared_from_this<PSUSensor>

     static constexpr size_t warnAfterErrorCount = 10;

+    // Wait timeout_before_clear (5 minutes)
+    static constexpr unsigned int timeout_before_clear = 300;
+
+    // Time of last clear
+    unsigned int lastClear;
+
+    // Pass true if read was successful, else pass false
+    // If the value returned is true, clear the value
+    bool readStatusClearValue(bool success);
+
   public:
     static constexpr double defaultSensorPoll = 1.0;
     static constexpr unsigned int defaultSensorPollMs =

On Mon, Jan 27, 2025 at 3:43 PM Mark Woodward <woodwardm at google.com> wrote:

> We are having an issue with psusensor in that when it is functioning with
> or without power, psusensor can read the status of the PSU. If the PSU is
> removed, the status of the PSU is never updated.
>
> It looks like in void PSUSensor::handleResponse() when there is a read
> error an error log string is output, restartRead () is called, but there is
> nothing done to the sensor data. This means that when a PSU is removed,
> aside from the log entry, there is no change to the sensor readings. It
> will just continue to report the last readings.
>
> Is a PoC, I added "updateValue(0 + sensorOffset);" in the error stanza, so
> that when the PSU is removed, the values are cleared.
>
> Is this expected behavior?
>
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