manager: Set up signal relay service, use it for MaxChargeLevelChanged

src/daemon/user.rs

@@ -21,7 +21,7 @@ use zbus::fdo::ObjectManager;
 
 use crate::daemon::{channel, Daemon, DaemonCommand, DaemonContext};
 use crate::job::{JobManager, JobManagerService};
-use crate::manager::user::create_interfaces;
+use crate::manager::user::{create_interfaces, SignalRelayService};
 use crate::path;
 use crate::power::TdpManagerService;
 use crate::udev::UdevMonitor;
@@ -114,6 +114,7 @@ async fn create_connections(
     Connection,
     JobManagerService,
     Result<TdpManagerService>,
+    SignalRelayService,
 )> {
     let system = Connection::system().await?;
     let connection = Builder::session()?
@@ -133,9 +134,16 @@ async fn create_connections(
         None
     };
 
-    create_interfaces(connection.clone(), system.clone(), channel, jm_tx, tdp_tx).await?;
+    let signal_relay_service =
+        create_interfaces(connection.clone(), system.clone(), channel, jm_tx, tdp_tx).await?;
 
-    Ok((connection, system, jm_service, tdp_service))
+    Ok((
+        connection,
+        system,
+        jm_service,
+        tdp_service,
+        signal_relay_service,
+    ))
 }
 
 pub async fn daemon() -> Result<()> {
@@ -146,20 +154,22 @@ pub async fn daemon() -> Result<()> {
     let subscriber = Registry::default().with(stdout_log);
     let (tx, rx) = channel::<UserContext>();
 
-    let (session, system, mirror_service, tdp_service) = match create_connections(tx).await {
-        Ok(c) => c,
-        Err(e) => {
-            let _guard = tracing::subscriber::set_default(subscriber);
-            error!("Error connecting to DBus: {}", e);
-            bail!(e);
-        }
-    };
+    let (session, system, mirror_service, tdp_service, signal_relay_service) =
+        match create_connections(tx).await {
+            Ok(c) => c,
+            Err(e) => {
+                let _guard = tracing::subscriber::set_default(subscriber);
+                error!("Error connecting to DBus: {}", e);
+                bail!(e);
+            }
+        };
 
     let context = UserContext {
         session: session.clone(),
     };
     let mut daemon = Daemon::new(subscriber, system, rx).await?;
 
+    daemon.add_service(signal_relay_service);
     daemon.add_service(mirror_service);
     if let Ok(tdp_service) = tdp_service {
         daemon.add_service(tdp_service);

src/manager/root.rs

@@ -10,6 +10,7 @@ use anyhow::{anyhow, Result};
 use std::collections::HashMap;
 use std::ffi::OsStr;
 use tokio::fs::File;
+use tokio::spawn;
 use tokio::sync::mpsc::Sender;
 use tokio::sync::oneshot;
 use tracing::{error, info};
@@ -29,7 +30,7 @@ use crate::platform::platform_config;
 use crate::power::{
     set_cpu_scaling_governor, set_gpu_clocks, set_gpu_performance_level, set_gpu_power_profile,
     set_max_charge_level, set_platform_profile, tdp_limit_manager, CPUScalingGovernor,
-    GPUPerformanceLevel, GPUPowerProfile, TdpLimitManager,
+    GPUPerformanceLevel, GPUPowerProfile, SysfsWritten, TdpLimitManager,
 };
 use crate::process::{run_script, script_output};
 use crate::wifi::{
@@ -444,10 +445,34 @@ impl SteamOSManager {
             .map_err(to_zbus_fdo_error)
     }
 
-    async fn set_max_charge_level(&self, level: i32) -> fdo::Result<()> {
-        set_max_charge_level(if level == -1 { 0 } else { level })
+    #[zbus(signal)]
+    async fn max_charge_level_changed(signal_emitter: &SignalEmitter<'_>) -> zbus::Result<()>;
+
+    async fn set_max_charge_level(
+        &self,
+        level: i32,
+        #[zbus(connection)] connection: &Connection,
+    ) -> fdo::Result<()> {
+        let written = set_max_charge_level(if level == -1 { 0 } else { level })
             .await
-            .map_err(to_zbus_fdo_error)
+            .map_err(to_zbus_fdo_error)?;
+        let connection = connection.clone();
+        spawn(async move {
+            match written.await {
+                Ok(SysfsWritten::Written(res)) => {
+                    if let Ok(interface) = connection
+                        .object_server()
+                        .interface::<_, Self>("/com/steampowered/SteamOSManager1")
+                        .await
+                    {
+                        interface.max_charge_level_changed().await?;
+                    }
+                    res
+                }
+                _ => Ok(()),
+            }
+        });
+        Ok(())
     }
 
     async fn set_performance_profile(&self, profile: &str) -> fdo::Result<()> {

src/manager/user.rs

@@ -10,6 +10,7 @@ use anyhow::{Error, Result};
 use std::collections::HashMap;
 use tokio::sync::mpsc::{Sender, UnboundedSender};
 use tokio::sync::oneshot;
+use tokio_stream::StreamExt;
 use tracing::error;
 use zbus::object_server::SignalEmitter;
 use zbus::proxy::{Builder, CacheProperties};
@@ -35,7 +36,7 @@ use crate::screenreader::{OrcaManager, ScreenReaderMode};
 use crate::wifi::{
     get_wifi_backend, get_wifi_power_management_state, list_wifi_interfaces, WifiBackend,
 };
-use crate::API_VERSION;
+use crate::{Service, API_VERSION};
 
 pub(crate) const MANAGER_PATH: &str = "/com/steampowered/SteamOSManager1";
 
@@ -185,6 +186,11 @@ struct WifiPowerManagement1 {
     proxy: Proxy<'static>,
 }
 
+pub(crate) struct SignalRelayService {
+    proxy: Proxy<'static>,
+    session: Connection,
+}
+
 impl SteamOSManager {
     pub async fn new(
         system_conn: Connection,
@@ -275,13 +281,8 @@ impl BatteryChargeLimit1 {
     }
 
     #[zbus(property)]
-    async fn set_max_charge_level(
-        &self,
-        limit: i32,
-        #[zbus(signal_emitter)] ctx: SignalEmitter<'_>,
-    ) -> zbus::Result<()> {
-        let _: () = self.proxy.call("SetMaxChargeLevel", &(limit)).await?;
-        self.max_charge_level_changed(&ctx).await
+    async fn set_max_charge_level(&self, limit: i32) -> zbus::Result<()> {
+        self.proxy.call("SetMaxChargeLevel", &(limit)).await
     }
 
     #[zbus(property(emits_changed_signal = "const"))]
@@ -874,6 +875,33 @@ impl WifiPowerManagement1 {
     }
 }
 
+impl Service for SignalRelayService {
+    const NAME: &'static str = "signal-relay";
+
+    async fn run(&mut self) -> Result<()> {
+        let Ok(battery_charge_limit) = self
+            .session
+            .object_server()
+            .interface::<_, BatteryChargeLimit1>(MANAGER_PATH)
+            .await
+        else {
+            return Ok(());
+        };
+        let ctx = battery_charge_limit.signal_emitter();
+
+        let mut max_charge_level_changed =
+            self.proxy.receive_signal("MaxChargeLevelChanged").await?;
+        loop {
+            max_charge_level_changed.next().await;
+            battery_charge_limit
+                .get()
+                .await
+                .max_charge_level_changed(ctx)
+                .await?;
+        }
+    }
+}
+
 async fn create_platform_interfaces(
     proxy: &Proxy<'static>,
     object_server: &ObjectServer,
@@ -1014,7 +1042,7 @@ pub(crate) async fn create_interfaces(
     daemon: Sender<Command>,
     job_manager: UnboundedSender<JobManagerCommand>,
     tdp_manager: Option<UnboundedSender<TdpManagerCommand>>,
-) -> Result<()> {
+) -> Result<SignalRelayService> {
     let proxy = Builder::<Proxy>::new(&system)
         .destination("com.steampowered.SteamOSManager1")?
         .path("/com/steampowered/SteamOSManager1")?
@@ -1111,7 +1139,7 @@ pub(crate) async fn create_interfaces(
             .await?;
     }
 
-    Ok(())
+    Ok(SignalRelayService { session, proxy })
 }
 
 #[cfg(test)]

src/power.rs

@@ -681,7 +681,7 @@ pub(crate) async fn get_max_charge_level() -> Result<i32> {
         .map_err(|e| anyhow!("Error parsing value: {e}"))
 }
 
-pub(crate) async fn set_max_charge_level(limit: i32) -> Result<()> {
+pub(crate) async fn set_max_charge_level(limit: i32) -> Result<oneshot::Receiver<SysfsWritten>> {
     ensure!((0..=100).contains(&limit), "Invalid limit");
     let data = limit.to_string();
     let config = device_config().await?;
@@ -691,9 +691,14 @@ pub(crate) async fn set_max_charge_level(limit: i32) -> Result<()> {
         .ok_or(anyhow!("No battery charge limit configured"))?;
     let base = find_hwmon(config.hwmon_name.as_str()).await?;
 
-    write_synced(base.join(config.attribute.as_str()), data.as_bytes())
-        .await
-        .inspect_err(|message| error!("Error writing to sysfs file: {message}"))
+    Ok(SYSFS_WRITER
+        .get()
+        .ok_or(anyhow!("sysfs writer not running"))?
+        .send(
+            base.join(config.attribute.clone()),
+            data.as_bytes().to_owned(),
+        )
+        .await)
 }
 
 pub(crate) async fn get_available_platform_profiles(name: &str) -> Result<Vec<String>> {
@@ -1650,11 +1655,11 @@ CCLK_RANGE in Core0:
 
         assert_eq!(get_max_charge_level().await.unwrap(), 10);
 
-        set_max_charge_level(99).await.expect("set");
-        assert_eq!(get_max_charge_level().await.unwrap(), 99);
+        write(base.join("max_battery_charge_level"), "99\n")
+            .await
+            .expect("write");
 
-        set_max_charge_level(0).await.expect("set");
-        assert_eq!(get_max_charge_level().await.unwrap(), 0);
+        assert_eq!(get_max_charge_level().await.unwrap(), 99);
 
         assert!(set_max_charge_level(101).await.is_err());
         assert!(set_max_charge_level(-1).await.is_err());