cpu: clean up dynamic CPU turbo management

src/config/types.rs

@@ -124,6 +124,7 @@ pub struct ProfileConfigToml {
     pub min_freq_mhz: Option<u32>,
     pub max_freq_mhz: Option<u32>,
     pub platform_profile: Option<String>,
+    pub turbo_auto_settings: Option<TurboAutoSettings>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub battery_charge_thresholds: Option<BatteryChargeThresholds>,
 }
@@ -151,6 +152,7 @@ impl Default for ProfileConfigToml {
             min_freq_mhz: None,
             max_freq_mhz: None,
             platform_profile: None,
+            turbo_auto_settings: None,
             battery_charge_thresholds: None,
         }
     }
@@ -208,7 +210,9 @@ impl From<ProfileConfigToml> for ProfileConfig {
             min_freq_mhz: toml_config.min_freq_mhz,
             max_freq_mhz: toml_config.max_freq_mhz,
             platform_profile: toml_config.platform_profile,
-            turbo_auto_settings: Some(TurboAutoSettings::default()),
+            turbo_auto_settings: toml_config
+                .turbo_auto_settings
+                .or_else(|| Some(TurboAutoSettings::default())),
             battery_charge_thresholds: toml_config.battery_charge_thresholds,
         }
     }

src/cpu.rs

@@ -1,6 +1,7 @@
 use crate::core::{GovernorOverrideMode, TurboSetting};
 use crate::util::error::ControlError;
 use core::str;
+use log::debug;
 use std::{fs, io, path::Path, string::ToString};
 
 pub type Result<T, E = ControlError> = std::result::Result<T, E>;
@@ -216,12 +217,19 @@ pub fn set_turbo(setting: TurboSetting) -> Result<()> {
     let value_pstate = match setting {
         TurboSetting::Always => "0", // no_turbo = 0 means turbo is enabled
         TurboSetting::Never => "1",  // no_turbo = 1 means turbo is disabled
-        TurboSetting::Auto => return Err(ControlError::InvalidValueError("Turbo Auto cannot be directly set via intel_pstate/no_turbo or cpufreq/boost. System default.".to_string())),
+        // Auto mode is handled at the engine level, not directly at the sysfs level
+        TurboSetting::Auto => {
+            debug!("Turbo Auto mode is managed by engine logic based on system conditions");
+            return Ok(());
+        }
     };
     let value_boost = match setting {
         TurboSetting::Always => "1", // boost = 1 means turbo is enabled
         TurboSetting::Never => "0",  // boost = 0 means turbo is disabled
-        TurboSetting::Auto => return Err(ControlError::InvalidValueError("Turbo Auto cannot be directly set via intel_pstate/no_turbo or cpufreq/boost. System default.".to_string())),
+        TurboSetting::Auto => {
+            debug!("Turbo Auto mode is managed by engine logic based on system conditions");
+            return Ok(());
+        }
     };
 
     // AMD specific paths

src/engine.rs

@@ -4,6 +4,7 @@ use crate::core::{OperationalMode, SystemReport, TurboSetting};
 use crate::cpu::{self};
 use crate::util::error::{ControlError, EngineError};
 use log::{debug, info, warn};
+use std::sync::atomic::{AtomicBool, Ordering};
 
 /// Try applying a CPU feature and handle common error cases. Centralizes the where we
 /// previously did:
@@ -172,6 +173,10 @@ pub fn determine_and_apply_settings(
     Ok(())
 }
 
+// Keep track of current auto turbo state for hysteresis using thread-safe atomics
+static PREVIOUS_TURBO_STATE: AtomicBool = AtomicBool::new(false);
+static TURBO_STATE_INITIALIZED: AtomicBool = AtomicBool::new(false);
+
 fn manage_auto_turbo(report: &SystemReport, config: &ProfileConfig) -> Result<(), EngineError> {
     // Get the auto turbo settings from the config, or use defaults
     let turbo_settings = config.turbo_auto_settings.clone().unwrap_or_default();
@@ -204,10 +209,18 @@ fn manage_auto_turbo(report: &SystemReport, config: &ProfileConfig) -> Result<()
         }
     };
 
-    // Decision logic for enabling/disabling turbo
-    let enable_turbo = match (cpu_temp, avg_cpu_usage) {
+    // Get previous state safely using atomic operations
+    let has_previous_state = TURBO_STATE_INITIALIZED.load(Ordering::Relaxed);
+    let previous_turbo_enabled = if has_previous_state {
+        Some(PREVIOUS_TURBO_STATE.load(Ordering::Relaxed))
+    } else {
+        None
+    };
+
+    // Decision logic for enabling/disabling turbo with hysteresis
+    let enable_turbo = match (cpu_temp, avg_cpu_usage, previous_turbo_enabled) {
         // If temperature is too high, disable turbo regardless of load
-        (Some(temp), _) if temp >= turbo_settings.temp_threshold_high => {
+        (Some(temp), _, _) if temp >= turbo_settings.temp_threshold_high => {
             info!(
                 "Auto Turbo: Disabled due to high temperature ({:.1}°C >= {:.1}°C)",
                 temp, turbo_settings.temp_threshold_high
@@ -215,7 +228,7 @@ fn manage_auto_turbo(report: &SystemReport, config: &ProfileConfig) -> Result<()
             false
         }
         // If load is high enough, enable turbo (unless temp already caused it to disable)
-        (_, Some(usage)) if usage >= turbo_settings.load_threshold_high => {
+        (_, Some(usage), _) if usage >= turbo_settings.load_threshold_high => {
             info!(
                 "Auto Turbo: Enabled due to high CPU load ({:.1}% >= {:.1}%)",
                 usage, turbo_settings.load_threshold_high
@@ -223,21 +236,36 @@ fn manage_auto_turbo(report: &SystemReport, config: &ProfileConfig) -> Result<()
             true
         }
         // If load is low, disable turbo
-        (_, Some(usage)) if usage <= turbo_settings.load_threshold_low => {
+        (_, Some(usage), _) if usage <= turbo_settings.load_threshold_low => {
             info!(
                 "Auto Turbo: Disabled due to low CPU load ({:.1}% <= {:.1}%)",
                 usage, turbo_settings.load_threshold_low
             );
             false
         }
-        // In intermediate load scenarios or if we can't determine, leave turbo in current state
-        // For now, we'll disable it as a safe default
+        // In intermediate load range, maintain previous state (hysteresis)
+        (_, Some(usage), Some(prev_state))
+            if usage > turbo_settings.load_threshold_low
+                && usage < turbo_settings.load_threshold_high =>
+        {
+            info!(
+                "Auto Turbo: Maintaining previous state ({}) due to intermediate load ({:.1}%)",
+                if prev_state { "enabled" } else { "disabled" },
+                usage
+            );
+            prev_state
+        }
+        // In indeterminate states or unknown previous state, default to disabled
         _ => {
             info!("Auto Turbo: Disabled (default for indeterminate state)");
             false
         }
     };
 
+    // Save the current state for next time using atomic operations
+    PREVIOUS_TURBO_STATE.store(enable_turbo, Ordering::Relaxed);
+    TURBO_STATE_INITIALIZED.store(true, Ordering::Relaxed);
+
     // Apply the turbo setting
     let turbo_setting = if enable_turbo {
         TurboSetting::Always