fix: sync Intel WMI CPU power limits to RAPL powercap interfaces

rog-platform/src/asus_armoury.rs

@@ -53,6 +53,63 @@ pub struct Attribute {
     base_path: PathBuf,
 }
 
+fn is_intel_cpu() -> bool {
+    std::fs::read_to_string("/proc/cpuinfo")
+        .map(|content| content.contains("GenuineIntel"))
+        .unwrap_or(false)
+}
+
+fn write_intel_rapl_limit(constraint_idx: u32, watts: i32) {
+    let microwatts_str = ((watts as u64) * 1_000_000).to_string();
+    let file_name = format!("constraint_{}_power_limit_uw", constraint_idx);
+    let Ok(entries) = read_dir("/sys/class/powercap") else {
+        return;
+    };
+    for entry in entries.flatten() {
+        let zone = entry.file_name();
+        let zone = zone.to_string_lossy();
+        // A package zone name has exactly one ':' ("intel-rapl:0"). Sub-zones have two ("intel-rapl:0:0").
+        let is_package_zone = (zone.starts_with("intel-rapl:")
+            || zone.starts_with("intel-rapl-mmio:"))
+            && zone.matches(':').count() == 1;
+        if !is_package_zone {
+            continue;
+        }
+        let path = entry.path().join(&file_name);
+        if path.exists() {
+            debug!("Writing {microwatts_str} to {}", path.display());
+            if let Ok(mut file) = OpenOptions::new().write(true).open(&path) {
+                let _ = file.write_all(microwatts_str.as_bytes());
+            }
+        }
+    }
+}
+
+fn sync_all_intel_rapl_limits() {
+    if !is_intel_cpu() {
+        return;
+    }
+
+    let base_dir = Path::new("/sys/class/firmware-attributes/asus-armoury/attributes");
+
+    let limits = [
+        ("ppt_pl1_spl", 0),
+        ("ppt_pl2_sppt", 1),
+        ("ppt_pl3_fppt", 2),
+    ];
+
+    for (attr_name, constraint_idx) in &limits {
+        let current_value_path = base_dir.join(attr_name).join("current_value");
+        if current_value_path.exists() {
+            if let Ok(val_str) = std::fs::read_to_string(&current_value_path) {
+                if let Ok(watts) = val_str.trim().parse::<i32>() {
+                    write_intel_rapl_limit(*constraint_idx, watts);
+                }
+            }
+        }
+    }
+}
+
 impl Attribute {
     pub fn name(&self) -> &str {
         &self.name
@@ -97,6 +154,12 @@ impl Attribute {
 
         let mut file = OpenOptions::new().write(true).open(&path)?;
         file.write_all(value_str.as_bytes())?;
+
+        if self.name == "ppt_pl1_spl" || self.name == "ppt_pl2_sppt" || self.name == "ppt_pl3_fppt"
+        {
+            sync_all_intel_rapl_limits();
+        }
+
         Ok(())
     }