feat: added better fan control for M3/M4 Apple Silicon (#2924)

* Fix Ftst key handling for Apple Silicon fan control

* Update CFBundleVersion to 747 in Info.plist

Signed-off-by: Alex Goodkind <alex@goodkind.io>

* Update TeamId and SMC.Helper certificate identifier in Info.plist

Signed-off-by: Alex Goodkind <alex@goodkind.io>

* Add debug logging to SMC fan control functions

* Use writeWithRetry for Apple Silicon fan control writes and bump helper version to 1.0.3

* SMC fan control: serialize ops, Ftst timing, verification, logging

- Helper: serial queue for setFanMode/setFanSpeed/resetFanControl
- smc.swift: 3s wait after Ftst=1, longer mode retry (100ms), SMC result logging
- helpers: per-fan verification with cancel-on-supersede, clearer logs
- smc.swift: neutral write logs (no 'succeeded'), FAILED on error

* - Updated error handling in SMCHelper to suppress expected XPC errors (codes 4097 and 4099) during helper updates/restarts.
- Removed unnecessary debug print statement in ModeButtons for improved log clarity.

* Update version numbers in Info.plist files to 752 and change TeamId for SMC.Helper

* Add FanMode.auto3 and isAutomatic, re-add F%dMd write in automatic path, use isAutomatic in countManualFans; bump SMC Helper to 1.0.24

* Apple Silicon fan control: direct-first writes, strip diagnostic bloat

Try direct F%dMd=1 write before Ftst unlock (instant on M1, fallback
on M3/M4). Remove verification system, diagnostic prints, dead code.

* Apple Silicon fan control: direct-first writes

Try direct F%dMd=1 write before Ftst unlock (instant on M1,
fallback on M3/M4).

Bump helper to 1.0.2/3, Stats/Widgets to 751.

---------

Signed-off-by: Alex Goodkind <alex@goodkind.io>

Kit/helpers.swift

@@ -894,6 +894,11 @@ public class SMCHelper {
         }
     }
     
+    public func resetFanControl() {
+        guard let helper = self.helper(nil) else { return }
+        helper.resetFanControl { _ in }
+    }
+    
     public func isActive() -> Bool {
         return self.connection != nil
     }

Kit/types.swift

@@ -271,6 +271,7 @@ public extension Notification.Name {
     static let refreshPublicIP = Notification.Name("refreshPublicIP")
     static let resetTotalNetworkUsage = Notification.Name("resetTotalNetworkUsage")
     static let syncFansControl = Notification.Name("syncFansControl")
+    static let checkFanModes = Notification.Name("checkFanModes")
     static let fanHelperState = Notification.Name("fanHelperState")
     static let toggleOneView = Notification.Name("toggleOneView")
     static let widgetRearrange = Notification.Name("widgetRearrange")

Modules/Sensors/popup.swift

@@ -71,8 +71,24 @@ internal class Popup: PopupWrapper {
                 selected: self.fanValueState.rawValue
             ))
         ]))
+        #if arch(arm64)
+        NotificationCenter.default.addObserver(self, selector: #selector(self.checkFanModesAndResetFtst), name: .checkFanModes, object: nil)
+        #endif
     }
     
+    deinit {
+        NotificationCenter.default.removeObserver(self)
+    }
+    
+    #if arch(arm64)
+    @objc private func checkFanModesAndResetFtst() {
+        let fanViews = self.list.values.compactMap { $0 as? FanView }
+        guard !fanViews.isEmpty else { return }
+        guard fanViews.allSatisfy({ $0.fan.mode == .automatic }) else { return }
+        SMCHelper.shared.resetFanControl()
+    }
+    #endif
+    
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
@@ -455,7 +471,7 @@ internal class ChartSensorView: NSStackView {
 internal class FanView: NSStackView {
     public var sizeCallback: (() -> Void)
     
-    private var fan: Fan
+    internal var fan: Fan
     private var ready: Bool = false
     
     private var helperView: NSView? = nil
@@ -638,7 +654,7 @@ internal class FanView: NSStackView {
             height: view.frame.height - 8
         ), mode: self.fan.mode)
         buttons.callback = { [weak self] (mode: FanMode) in
-            if let fan = self?.fan, fan.mode != mode {
+            if let fan = self?.fan, mode == .automatic || fan.mode != mode {
                 self?.fan.mode = mode
                 self?.fan.customMode = mode
                 SMCHelper.shared.setFanMode(fan.id, mode: mode.rawValue)
@@ -1072,6 +1088,7 @@ private class ModeButtons: NSStackView {
         self.callback(.automatic)
         
         NotificationCenter.default.post(name: .syncFansControl, object: nil, userInfo: ["mode": "automatic"])
+        NotificationCenter.default.post(name: .checkFanModes, object: nil)
     }
     
     @objc private func manualMode(_ sender: NSButton) {

Modules/Sensors/readers.swift

@@ -352,6 +352,14 @@ extension SensorsReader {
     }
     
     private func getFanMode(_ id: Int) -> FanMode {
+        #if arch(arm64)
+        // Apple Silicon: Read F%dMd directly
+        // Mode values: 0 = auto, 1 = manual, 3 = system (treated as auto for UI)
+        let modeValue = Int(SMC.shared.getValue("F\(id)Md") ?? 0)
+        return modeValue == 1 ? .forced : .automatic
+        #else
+        // Legacy Intel: Use FS! bitmask
+        // Bitmask: 0 = all auto, 1 = fan 0 forced, 2 = fan 1 forced, 3 = both forced
         let fansMode: Int = Int(SMC.shared.getValue("FS! ") ?? 0)
         var mode: FanMode = .automatic
         
@@ -366,6 +374,7 @@ extension SensorsReader {
         }
         
         return mode
+        #endif
     }
 }
 

SMC/Helper/Info.plist

@@ -7,9 +7,9 @@
 	<key>CFBundleName</key>
 	<string>eu.exelban.Stats.SMC.Helper</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0.1</string>
+	<string>1.1.0</string>
 	<key>CFBundleVersion</key>
-	<string>2</string>
+	<string>3</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>SMAuthorizedClients</key>

SMC/Helper/main.swift

@@ -16,6 +16,7 @@ helper.run()
 
 class Helper: NSObject, NSXPCListenerDelegate, HelperProtocol {
     private let listener: NSXPCListener
+    private let smcQueue = DispatchQueue(label: "eu.exelban.Stats.SMC.Helper.smcQueue")
     
     private var connections = [NSXPCConnection]()
     private var shouldQuit = false
@@ -115,36 +116,56 @@ extension Helper {
     }
     
     func setFanMode(id: Int, mode: Int, completion: (String?) -> Void) {
-        guard let smc = self.smc else {
+        smcQueue.sync {
-            completion("missing smc tool")
+            guard let smc = self.smc else {
-            return
+                completion("missing smc tool")
-        }
+                return
-        let result = syncShell("\(smc) fan \(id) -m \(mode)")
+            }
+            let result = syncShell("\(smc) fan \(id) -m \(mode)")
             
-        if let error = result.error, !error.isEmpty {
+            if let error = result.error, !error.isEmpty {
-            NSLog("error set fan mode: \(error)")
+                NSLog("error set fan mode: \(error)")
-            completion(nil)
+                completion(nil)
-            return
+                return
-        }
+            }
             
-        completion(result.output)
+            completion(result.output)
+        }
     }
     
     func setFanSpeed(id: Int, value: Int, completion: (String?) -> Void) {
-        guard let smc = self.smc else {
+        smcQueue.sync {
-            completion("missing smc tool")
+            guard let smc = self.smc else {
-            return
+                completion("missing smc tool")
+                return
+            }
+            
+            let result = syncShell("\(smc) fan \(id) -v \(value)")
+            
+            if let error = result.error, !error.isEmpty {
+                NSLog("error set fan speed: \(error)")
+                completion(nil)
+                return
+            }
+            
+            completion(result.output)
         }
+    }
     
-        let result = syncShell("\(smc) fan \(id) -v \(value)")
+    func resetFanControl(completion: (String?) -> Void) {
-        
+        smcQueue.sync {
-        if let error = result.error, !error.isEmpty {
+            guard let smc = self.smc else {
-            NSLog("error set fan speed: \(error)")
+                completion("missing smc tool")
-            completion(nil)
+                return
-            return
+            }
+            let result = syncShell("\(smc) reset")
+            if let error = result.error, !error.isEmpty {
+                NSLog("error reset fan control: \(error)")
+                completion(nil)
+                return
+            }
+            completion(result.output)
         }
-        
-        completion(result.output)
     }
     
     func powermetrics(_ samplers: [String], completion: @escaping (String?) -> Void) {

SMC/Helper/protocol.swift

@@ -17,6 +17,7 @@ import Foundation
     
     func setFanMode(id: Int, mode: Int, completion: @escaping (String?) -> Void)
     func setFanSpeed(id: Int, value: Int, completion: @escaping (String?) -> Void)
+    func resetFanControl(completion: @escaping (String?) -> Void)
     func powermetrics(_ samplers: [String], completion: @escaping (String?) -> Void)
     
     func uninstall()

SMC/main.swift

@@ -16,6 +16,7 @@ enum CMDType: String {
     case set
     case fan
     case fans
+    case reset
     case help
     case unknown
     
@@ -25,6 +26,7 @@ enum CMDType: String {
         case "set": self = .set
         case "fan": self = .fan
         case "fans": self = .fans
+        case "reset": self = .reset
         case "help": self = .help
         default: self = .unknown
         }
@@ -136,6 +138,16 @@ func main() {
             
             print()
         }
+    case .reset:
+        #if arch(arm64)
+        if SMC.shared.resetFanControl() {
+            print("[reset] Ftst reset to 0, thermalmonitord has control")
+        } else {
+            print("[reset] Ftst reset FAILED")
+        }
+        #else
+        print("[reset] not needed on Intel Macs")
+        #endif
     case .help, .unknown:
         print("SMC tool\n")
         print("Usage:")
@@ -145,6 +157,7 @@ func main() {
         print("  set      set value to a key")
         print("  fan      set fan speed")
         print("  fans     list of fans")
+        print("  reset    reset Ftst (Apple Silicon only)")
         print("  help     help menu\n")
         print("Available Flags:")
         print("  -t    list temperature sensors")

SMC/smc.swift

@@ -46,6 +46,11 @@ internal enum SMCKeys: UInt8 {
 public enum FanMode: Int, Codable {
     case automatic = 0
     case forced = 1
+    case auto3 = 3
+
+    public var isAutomatic: Bool {
+        self == .automatic || self == .auto3
+    }
 }
 
 internal struct SMCKeyData_t {
@@ -352,6 +357,43 @@ public class SMC {
     // MARK: - fans
     
     public func setFanMode(_ id: Int, mode: FanMode) {
+        #if arch(arm64)
+        if mode == .forced {
+            if !unlockFanControl(fanId: id) { return }
+        } else {
+            let modeKey = "F\(id)Md"
+            let targetKey = "F\(id)Tg"
+            
+            if self.getValue(modeKey) != nil {
+                var modeVal = SMCVal_t(modeKey)
+                let readResult = read(&modeVal)
+                guard readResult == kIOReturnSuccess else {
+                    print(smcError("read", key: modeKey, result: readResult))
+                    return
+                }
+                if modeVal.bytes[0] != 0 {
+                    modeVal.bytes[0] = 0
+                    if !writeWithRetry(modeVal) { return }
+                }
+            }
+            
+            var targetValue = SMCVal_t(targetKey)
+            let result = read(&targetValue)
+            guard result == kIOReturnSuccess else {
+                print(smcError("read", key: targetKey, result: result))
+                return
+            }
+            
+            let bytes = Float(0).bytes
+            targetValue.bytes[0] = bytes[0]
+            targetValue.bytes[1] = bytes[1]
+            targetValue.bytes[2] = bytes[2]
+            targetValue.bytes[3] = bytes[3]
+            
+            if !writeWithRetry(targetValue) { return }
+        }
+        #else
+        // Intel
         if self.getValue("F\(id)Md") != nil {
             var result: kern_return_t = 0
             var value = SMCVal_t("F\(id)Md")
@@ -422,15 +464,26 @@ public class SMC {
             print("Error write: " + (String(cString: mach_error_string(result), encoding: String.Encoding.ascii) ?? "unknown error"))
             return
         }
+        #endif
     }
     
     public func setFanSpeed(_ id: Int, speed: Int) {
-        let maxSpeed = Int(self.getValue("F\(id)Mx") ?? 4000)
+        if let maxSpeed = self.getValue("F\(id)Mx"),
+           speed > Int(maxSpeed) {
+            return setFanSpeed(id, speed: Int(maxSpeed))
+        }
         
-        if speed > maxSpeed {
+        #if arch(arm64)
-            print("new fan speed (\(speed)) is more than maximum speed (\(maxSpeed))")
+        var modeVal = SMCVal_t("F\(id)Md")
+        let modeResult = read(&modeVal)
+        guard modeResult == kIOReturnSuccess else {
+            print("Error read fan mode: " + (String(cString: mach_error_string(modeResult), encoding: String.Encoding.ascii) ?? "unknown error"))
             return
         }
+        if modeVal.bytes[0] != 1 {
+            if !unlockFanControl(fanId: id) { return }
+        }
+        #endif
         
         var result: kern_return_t = 0
         var value = SMCVal_t("F\(id)Tg")
@@ -454,11 +507,17 @@ public class SMC {
             value.bytes[3] = UInt8(0)
         }
         
+        #if arch(arm64)
+        if !writeWithRetry(value) {
+            return
+        }
+        #else
         result = write(value)
         if result != kIOReturnSuccess {
             print("Error write: " + (String(cString: mach_error_string(result), encoding: String.Encoding.ascii) ?? "unknown error"))
             return
         }
+        #endif
     }
     
     public func resetFans() {
@@ -471,6 +530,101 @@ public class SMC {
         }
     }
     
+    // MARK: - Apple Silicon Fan Control
+    
+    #if arch(arm64)
+    /// Format SMC error for logging with context
+    private func smcError(_ operation: String, key: String, result: kern_return_t) -> String {
+        let errorDesc = String(cString: mach_error_string(result), encoding: String.Encoding.ascii) ?? "unknown error"
+        return "[\(key)] \(operation) failed: \(errorDesc) (0x\(String(result, radix: 16)))"
+    }
+    
+    private func writeWithRetry(_ value: SMCVal_t, maxAttempts: Int = 10, delayMicros: UInt32 = 50_000) -> Bool {
+        let mutableValue = value
+        var lastResult: kern_return_t = kIOReturnSuccess
+        for attempt in 0..<maxAttempts {
+            lastResult = write(mutableValue)
+            if lastResult == kIOReturnSuccess {
+                return true
+            }
+            if attempt < maxAttempts - 1 {
+                usleep(delayMicros)
+            }
+        }
+        print(smcError("write", key: value.key, result: lastResult))
+        return false
+    }
+    
+    private func unlockFanControl(fanId: Int) -> Bool {
+        var ftstCheck = SMCVal_t("Ftst")
+        let ftstResult = read(&ftstCheck)
+        guard ftstResult == kIOReturnSuccess else {
+            print(smcError("read", key: "Ftst", result: ftstResult))
+            return false
+        }
+        let ftstActive = ftstCheck.bytes[0] == 1
+        
+        if ftstActive {
+            return retryModeWrite(fanId: fanId, maxAttempts: 20)
+        }
+        
+        // Try direct write first (works on M1 without Ftst)
+        let modeKey = "F\(fanId)Md"
+        var modeVal = SMCVal_t(modeKey)
+        let modeRead = read(&modeVal)
+        guard modeRead == kIOReturnSuccess else {
+            print(smcError("read", key: modeKey, result: modeRead))
+            return false
+        }
+        modeVal.bytes[0] = 1
+        if write(modeVal) == kIOReturnSuccess {
+            return true
+        }
+        
+        // Direct failed; fall back to Ftst unlock
+        var ftstVal = SMCVal_t("Ftst")
+        let ftstRead = read(&ftstVal)
+        guard ftstRead == kIOReturnSuccess else {
+            print(smcError("read", key: "Ftst", result: ftstRead))
+            return false
+        }
+        ftstVal.bytes[0] = 1
+        if !writeWithRetry(ftstVal, maxAttempts: 100) {
+            return false
+        }
+        
+        // Wait for thermalmonitord to yield control
+        usleep(3_000_000)
+        
+        return retryModeWrite(fanId: fanId, maxAttempts: 300)
+    }
+    
+    private func retryModeWrite(fanId: Int, maxAttempts: Int) -> Bool {
+        let modeKey = "F\(fanId)Md"
+        var modeVal = SMCVal_t(modeKey)
+        let result = read(&modeVal)
+        guard result == kIOReturnSuccess else {
+            print(smcError("read", key: modeKey, result: result))
+            return false
+        }
+        modeVal.bytes[0] = 1
+        return writeWithRetry(modeVal, maxAttempts: maxAttempts, delayMicros: 100_000)
+    }
+    
+    public func resetFanControl() -> Bool {
+        var value = SMCVal_t("Ftst")
+        let result = read(&value)
+        guard result == kIOReturnSuccess else {
+            print(smcError("read", key: "Ftst", result: result))
+            return false
+        }
+        if value.bytes[0] == 0 { return true }
+        value.bytes[0] = 0
+        return writeWithRetry(value)
+    }
+    
+    #endif
+    
     // MARK: - internal functions
     
     private func read(_ value: UnsafeMutablePointer<SMCVal_t>) -> kern_return_t {
@@ -520,6 +674,12 @@ public class SMC {
             return result
         }
         
+        // IOKit can return kIOReturnSuccess but SMC firmware may still reject the write.
+        // Check SMC-level result code (0x00 = success, non-zero = error)
+        if output.result != 0x00 {
+            return kIOReturnError
+        }
+        
         return kIOReturnSuccess
     }