Refactoring link status polling

src/bin/dual-iir.rs

@@ -69,7 +69,7 @@ const APP: () = {
         iir_state: [[iir::Vec5; IIR_CASCADE_LENGTH]; 2],
     }
 
-    #[init(spawn=[telemetry, settings_update])]
+    #[init(spawn=[telemetry, settings_update, ethernet_link])]
     fn init(c: init::Context) -> init::LateResources {
         // Configure the microcontroller
         let (mut stabilizer, _pounder) = hardware::setup(c.core, c.device);
@@ -91,6 +91,9 @@ const APP: () = {
         c.spawn.settings_update().unwrap();
         c.spawn.telemetry().unwrap();
 
+        // Spawn the ethernet link period check task.
+        c.spawn.ethernet_link().unwrap();
+
         // Enable ADC/DAC events
         stabilizer.adcs.0.start();
         stabilizer.adcs.1.start();
@@ -227,6 +230,12 @@ const APP: () = {
             .unwrap();
     }
 
+    #[task(priority = 1, resources=[network], schedule=[ethernet_link])]
+    fn ethernet_link(c: ethernet_link::Context) {
+        c.resources.network.processor.handle_link();
+        c.schedule.ethernet_link(c.scheduled + SystemTimer::ticks_from_secs(1)).unwrap();
+    }
+
     #[task(binds = ETH, priority = 1)]
     fn eth(_: eth::Context) {
         unsafe { stm32h7xx_hal::ethernet::interrupt_handler() }

src/bin/lockin.rs

@@ -94,7 +94,7 @@ const APP: () = {
         lockin: Lockin<4>,
     }
 
-    #[init(spawn=[settings_update, telemetry])]
+    #[init(spawn=[settings_update, telemetry, ethernet_link])]
     fn init(c: init::Context) -> init::LateResources {
         // Configure the microcontroller
         let (mut stabilizer, _pounder) = setup(c.core, c.device);
@@ -118,6 +118,9 @@ const APP: () = {
         c.spawn.settings_update().unwrap();
         c.spawn.telemetry().unwrap();
 
+        // Spawn the ethernet link servicing task.
+        c.spawn.ethernet_link().unwrap();
+
         // Enable ADC/DAC events
         stabilizer.adcs.0.start();
         stabilizer.adcs.1.start();
@@ -298,6 +301,12 @@ const APP: () = {
             .unwrap();
     }
 
+    #[task(priority = 1, resources=[network], schedule=[ethernet_link])]
+    fn ethernet_link(c: ethernet_link::Context) {
+        c.resources.network.processor.handle_link();
+        c.schedule.ethernet_link(c.scheduled + SystemTimer::ticks_from_secs(1)).unwrap();
+    }
+
     #[task(binds = ETH, priority = 1)]
     fn eth(_: eth::Context) {
         unsafe { stm32h7xx_hal::ethernet::interrupt_handler() }

src/net/mod.rs

@@ -47,7 +47,7 @@ pub enum NetworkState {
 /// A structure of Stabilizer's default network users.
 pub struct NetworkUsers<S: Default + Clone + Miniconf, T: Serialize> {
     pub miniconf: MiniconfClient<S>,
-    processor: NetworkProcessor,
+    pub processor: NetworkProcessor,
     stream: DataStream,
     generator: Option<BlockGenerator>,
     pub telemetry: TelemetryClient<T>,
@@ -143,12 +143,10 @@ where
             UpdateState::Updated => NetworkState::Updated,
         };
 
-        let result = match self.miniconf.update() {
+        match self.miniconf.update() {
             UpdateState::Updated => NetworkState::SettingsChanged,
             UpdateState::NoChange => poll_result,
-        };
-
-        result
+        }
     }
 }
 

src/net/network_processor.rs

@@ -37,9 +37,25 @@ impl NetworkProcessor {
         }
     }
 
-    pub fn egress(&mut self) {
-        let now = self.clock.current_ms();
-        self.stack.lock(|stack| stack.poll(now)).ok();
+    /// Handle ethernet link connection status.
+    ///
+    /// # Note
+    /// This may take non-trivial amounts of time to communicate with the PHY. As such, this should
+    /// only be called as often as necessary (e.g. once per second or so).
+    pub fn handle_link(&mut self) {
+        // If the PHY indicates there's no more ethernet link, reset the DHCP server in the network
+        // stack.
+        match self.phy.poll_link() {
+            true => self.network_was_reset = false,
+
+            // Only reset the network stack once per link reconnection. This prevents us from
+            // sending an excessive number of DHCP requests.
+            false if !self.network_was_reset => {
+                self.network_was_reset = true;
+                self.stack.lock(|stack| stack.handle_link_reset());
+            }
+            _ => {}
+        };
     }
 
     /// Process and update the state of the network.
@@ -63,22 +79,6 @@ impl NetworkProcessor {
             }
         };
 
-        // If the PHY indicates there's no more ethernet link, reset the DHCP server in the network
-        // stack.
-        // TODO: Poll the link state in a task and handle resets. Polling this often is slow and
-        // uses necessary CPU time.
-        //match self.phy.poll_link() {
-        //    true => self.network_was_reset = false,
-
-        //    // Only reset the network stack once per link reconnection. This prevents us from
-        //    // sending an excessive number of DHCP requests.
-        //    false if !self.network_was_reset => {
-        //        self.network_was_reset = true;
-        //        self.stack.lock(|stack| stack.handle_link_reset());
-        //    }
-        //    _ => {}
-        //};
-
         result
     }
 }