Fix ASUS Z170 EC temperature read returning zero values

Adjust EC read logic so temperature registers (PCH, T_SENSOR, VRM)
return valid values on ASUS Z170 boards in user-mode.

Author: sergiye

OpenHardwareMonitorLib/Hardware/Motherboard/Identification.cs

@@ -383,6 +383,8 @@ public static Model GetModel(string name)
                 return Model.ROG_ZENITH_II_EXTREME;
             case var _ when name.Equals("Z170-A", StringComparison.OrdinalIgnoreCase):
                 return Model.Z170_A;
+            case var _ when name.Equals("Z170 PRO GAMING", StringComparison.OrdinalIgnoreCase):
+                return Model.Z170_PRO_GAMING;
             case var _ when name.Equals("B150M-C", StringComparison.OrdinalIgnoreCase):
                 return Model.B150M_C;
             case var _ when name.Equals("B150M-C D3", StringComparison.OrdinalIgnoreCase):

OpenHardwareMonitorLib/Hardware/Motherboard/Lpc/EC/EmbeddedController.cs

@@ -252,6 +252,11 @@ public abstract class EmbeddedController : Hardware
             ECSensor.FanWaterPump,
             ECSensor.CurrCPU,
             ECSensor.VoltageCPU),
+        new(Model.Z170_PRO_GAMING,
+            BoardFamily.Intel100,
+            ECSensor.TempChipset,
+            ECSensor.TempVrm,
+            ECSensor.TempTSensor),
         new(Model.PRIME_Z690_A,
             BoardFamily.Intel600,
             ECSensor.TempTSensor,
@@ -351,6 +356,7 @@ public abstract class EmbeddedController : Hardware
             BoardFamily.Intel100, new Dictionary<ECSensor, EmbeddedControllerSource>
             {
                 { ECSensor.TempChipset, new EmbeddedControllerSource("Chipset", SensorType.Temperature, 0x003a) },
+                { ECSensor.TempVrm, new EmbeddedControllerSource("VRM", SensorType.Temperature, 0x003e) },
                 { ECSensor.TempTSensor, new EmbeddedControllerSource("T Sensor", SensorType.Temperature, 0x003d, blank: -40) },
                 { ECSensor.FanWaterPump, new EmbeddedControllerSource("Water Pump", SensorType.Fan, 0x00bc, 2) },
                 { ECSensor.CurrCPU, new EmbeddedControllerSource("CPU", SensorType.Current, 0x00f4) },

OpenHardwareMonitorLib/Hardware/Motherboard/Lpc/EC/WindowsEmbeddedControllerIO.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Diagnostics;
+using System.Diagnostics;
 using System.Threading;
 
 namespace OpenHardwareMonitor.Hardware.Motherboard.Lpc.EC;
@@ -17,7 +16,7 @@ public class WindowsEmbeddedControllerIO : IEmbeddedControllerIO
     private const int FailuresBeforeSkip = 20;
     private const int MaxRetries = 5;
 
-    // implementation 
+    // implementation
     private const int WaitSpins = 50;
     private bool _disposed;
 
@@ -33,7 +32,7 @@ public WindowsEmbeddedControllerIO()
 
     public void Read(ushort[] registers, byte[] data)
     {
-        Trace.Assert(registers.Length <= data.Length, 
+        Trace.Assert(registers.Length <= data.Length,
                      "data buffer length has to be greater or equal to the registers array length");
 
         byte bank = 0;
@@ -58,15 +57,8 @@ public void Read(ushort[] registers, byte[] data)
         SwitchBank(prevBank);
     }
 
-    private byte ReadByte(byte register)
-    {
-        return ReadLoop<byte>(register, ReadByteOp);
-    }
-
-    private void WriteByte(byte register, byte value)
-    {
-        WriteLoop(register, value, WriteByteOp);
-    }
+    private byte ReadByte(byte register) => ReadLoop<byte>(register, ReadByteOp);
+    private void WriteByte(byte register, byte value) => WriteLoop(register, value, WriteByteOp);
 
     public void Dispose()
     {
@@ -84,7 +76,7 @@ private byte SwitchBank(byte bank)
         return previous;
     }
 
-    private TResult ReadLoop<TResult>(byte register, ReadOp<TResult> op) where TResult : new()
+    private static TResult ReadLoop<TResult>(byte register, ReadOp<TResult> op) where TResult : new()
     {
         TResult result = new();
 
@@ -99,7 +91,7 @@ private byte SwitchBank(byte bank)
         return result;
     }
 
-    private void WriteLoop<TValue>(byte register, TValue value, WriteOp<TValue> op)
+    private static void WriteLoop<TValue>(byte register, TValue value, WriteOp<TValue> op)
     {
         for (int i = 0; i < MaxRetries; i++)
         {
@@ -110,11 +102,11 @@ private void WriteLoop<TValue>(byte register, TValue value, WriteOp<TValue> op)
         }
     }
 
-    private bool WaitForStatus(Status status, bool isSet)
+    private static bool WaitForStatus(Status status, bool isSet)
     {
         for (int i = 0; i < WaitSpins; i++)
         {
-            byte value = ReadIOPort(Port.Command);
+            byte value = ReadIoPort(Port.Command);
 
             if (((byte)status & (!isSet ? value : (byte)~value)) == 0)
             {
@@ -134,10 +126,31 @@ private bool WaitRead()
             return true;
         }
 
-        if (WaitForStatus(Status.OutputBufferFull, true))
+        // Try OBF with reduced timeout
+        for (int i = 0; i < MaxRetries; i++)
         {
-            _waitReadFailures = 0;
-            return true;
+            byte status = ReadIoPort(Port.Command);
+            if ((status & (byte)Status.OutputBufferFull) != 0)
+            {
+                _waitReadFailures = 0;
+                return true;
+            }
+
+            Thread.Sleep(1);
+        }
+
+        // ASUS workaround: Wait for IBF to clear instead of OBF
+        // Testing on Z170 Pro Gaming shows IBF clears in 1-3ms when data is ready
+        for (int i = 0; i < WaitSpins; i++)
+        {
+            byte status = ReadIoPort(Port.Command);
+            if ((status & (byte)Status.InputBufferFull) == 0)
+            {
+                _waitReadFailures = 0;
+                return true;
+            }
+
+            Thread.Sleep(1);
         }
 
         _waitReadFailures++;
@@ -149,14 +162,49 @@ private bool WaitWrite()
         return WaitForStatus(Status.InputBufferFull, false);
     }
 
-    private byte ReadIOPort(Port port)
+    private static byte ReadIoPort(Port port) => Ring0.ReadIoPort((byte)port);
+
+    private static void WriteIoPort(Port port, byte datum) => Ring0.WriteIoPort((byte)port, datum);
+
+    protected bool ReadByteOp(byte register, out byte value)
     {
-        return Ring0.ReadIoPort((uint)port);
+        if (WaitWrite())
+        {
+            WriteIoPort(Port.Command, (byte)Command.Read);
+
+            if (WaitWrite())
+            {
+                WriteIoPort(Port.Data, register);
+
+                if (WaitWrite() && WaitRead())
+                {
+                    value = ReadIoPort(Port.Data);
+                    return true;
+                }
+            }
+        }
+
+        value = 0;
+        return false;
     }
 
-    private void WriteIOPort(Port port, byte datum)
+    protected bool WriteByteOp(byte register, byte value)
     {
-        Ring0.WriteIoPort((uint)port, datum);
+        if (WaitWrite())
+        {
+            WriteIoPort(Port.Command, (byte)Command.Write);
+            if (WaitWrite())
+            {
+                WriteIoPort(Port.Data, register);
+                if (WaitWrite())
+                {
+                    WriteIoPort(Port.Data, value);
+                    return true;
+                }
+            }
+        }
+
+        return false;
     }
 
     public class BusMutexLockingFailedException : EmbeddedController.IOException
@@ -195,49 +243,4 @@ private enum Status : byte
         SciEventPending = 0x20, // SCI_EVT
         SmiEventPending = 0x40 // SMI_EVT
     }
-
-    #region Read/Write ops
-
-    protected bool ReadByteOp(byte register, out byte value)
-    {
-        if (WaitWrite())
-        {
-            WriteIOPort(Port.Command, (byte)Command.Read);
-
-            if (WaitWrite())
-            {
-                WriteIOPort(Port.Data, register);
-
-                if (WaitWrite() && WaitRead())
-                {
-                    value = ReadIOPort(Port.Data);
-                    return true;
-                }
-            }
-        }
-
-        value = 0;
-        return false;
-    }
-
-    protected bool WriteByteOp(byte register, byte value)
-    {
-        if (WaitWrite())
-        {
-            WriteIOPort(Port.Command, (byte)Command.Write);
-            if (WaitWrite())
-            {
-                WriteIOPort(Port.Data, register);
-                if (WaitWrite())
-                {
-                    WriteIOPort(Port.Data, value);
-                    return true;
-                }
-            }
-        }
-
-        return false;
-    }
-
-    #endregion
 }

OpenHardwareMonitorLib/Hardware/Motherboard/Model.cs

@@ -103,6 +103,7 @@ public enum Model
     TUF_X470_PLUS_GAMING,
     TUF_GAMING_X870_PLUS_WIFI,
     Z170_A,
+    Z170_PRO_GAMING,
     B150M_C,
     B150M_C_D3,
     TUF_GAMING_X570_PLUS_WIFI,