Fix: do not crash if no battery is present

asusd/src/ctrl_platform.rs

@@ -295,16 +295,39 @@ impl CtrlPlatform {
 
     #[zbus(property)]
     fn charge_control_end_threshold(&self) -> Result<u8, FdoErr> {
-        let limit = self.power.get_charge_control_end_threshold()?;
+        if !self.power.has_charge_control_end_threshold() {
+            return Err(FdoErr::NotSupported(
+                "RogPlatform: charge_control_end_threshold not supported".to_owned(),
+            ));
+        }
+
+        let limit = self.power.get_charge_control_end_threshold().map_err(|e| {
+            FdoErr::Failed(format!(
+                "Could not read charge_control_end_threshold: {e:?}"
+            ))
+        })?;
+
         Ok(limit)
     }
 
     #[zbus(property)]
     async fn set_charge_control_end_threshold(&mut self, limit: u8) -> Result<(), FdoErr> {
+        if !self.power.has_charge_control_end_threshold() {
+            return Err(FdoErr::NotSupported(
+                "RogPlatform: charge_control_end_threshold not supported".to_owned(),
+            ));
+        }
+
         if !(20..=100).contains(&limit) {
             return Err(RogError::ChargeLimit(limit))?;
         }
-        self.power.set_charge_control_end_threshold(limit)?;
+
+        self.power
+            .set_charge_control_end_threshold(limit)
+            .map_err(|e| {
+                FdoErr::Failed(format!("Could not set charge_control_end_threshold: {e:?}"))
+            })?;
+
         self.config.lock().await.charge_control_end_threshold = limit;
         self.config.lock().await.base_charge_control_end_threshold = limit;
         self.config.lock().await.write();
@@ -312,12 +335,22 @@ impl CtrlPlatform {
     }
 
     async fn one_shot_full_charge(&self) -> Result<(), FdoErr> {
+        if !self.power.has_charge_control_end_threshold() {
+            return Err(FdoErr::NotSupported(
+                "RogPlatform: charge_control_end_threshold not supported".to_owned(),
+            ));
+        }
+
         let base_limit = std::mem::replace(
             &mut self.config.lock().await.charge_control_end_threshold,
             100,
         );
         if base_limit != 100 {
-            self.power.set_charge_control_end_threshold(100)?;
+            self.power
+                .set_charge_control_end_threshold(100)
+                .map_err(|e| {
+                    FdoErr::Failed(format!("Could not set one_shot_full_charge: {e:?}"))
+                })?;
             self.config.lock().await.base_charge_control_end_threshold = base_limit;
             self.config.lock().await.write();
         }

rog-platform/src/power.rs

@@ -101,8 +101,15 @@ impl AsusPower {
             });
         }
 
-        Err(PlatformError::MissingFunction(
+        // No battery found. Return an AsusPower with an empty battery path so
-            "Did not find a battery".to_owned(),
+        // callers can still be constructed and query `has_*` methods which
-        ))
+        // will correctly report absence. This avoids hard-failing on systems
+        // where the asus-nb-wmi driver loads on desktops with no battery.
+        info!("Did not find a battery, continuing without battery support");
+        Ok(Self {
+            mains,
+            battery: PathBuf::new(),
+            usb,
+        })
     }
 }