dut_power: simplify the error handling inside the thread

Since we can now return early from `wtb.spawn_thread`-spawned threads,
because they handle error propagation out of the thread context for us
we no longer have to use queues to send back error results manually.

Use that to simplify error handling in the thread setup and the steady
state.

Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de>

Author: hnez

src/dut_power.rs

@@ -338,7 +338,7 @@ impl DutPwrThread {
         // as well.
         // Use a queue to notify the calling thread if the priority setup
         // succeeded.
-        let (thread_res_tx, mut thread_res_rx) = bounded(1);
+        let (thread_tx, thread_rx) = bounded(1);
 
         // Spawn a high priority thread that handles the power status
         // in a realtimey fashion.
@@ -353,24 +353,20 @@ impl DutPwrThread {
             let mut volt_filter = MedianFilter::<4>::new();
             let mut curr_filter = MedianFilter::<4>::new();
 
-            let (tick_weak, request, state) = match realtime_priority() {
-                Ok(_) => {
-                    let tick = Arc::new(AtomicU32::new(0));
-                    let tick_weak = Arc::downgrade(&tick);
+            realtime_priority()?;
 
-                    let request = Arc::new(AtomicU8::new(OutputRequest::Idle as u8));
-                    let state = Arc::new(AtomicU8::new(OutputState::Off as u8));
+            let (tick_weak, request, state) = {
+                let tick = Arc::new(AtomicU32::new(0));
+                let tick_weak = Arc::downgrade(&tick);
 
-                    thread_res_tx
-                        .try_send(Ok((tick, request.clone(), state.clone())))
-                        .unwrap();
+                let request = Arc::new(AtomicU8::new(OutputRequest::Idle as u8));
+                let state = Arc::new(AtomicU8::new(OutputState::Off as u8));
 
-                    (tick_weak, request, state)
-                }
-                Err(e) => {
-                    thread_res_tx.try_send(Err(e)).unwrap();
-                    panic!()
-                }
+                thread_tx
+                    .try_send((tick, request.clone(), state.clone()))
+                    .expect("Queue that should be empty wasn't");
+
+                (tick_weak, request, state)
             };
 
             // The grace period contains the number of loop iterations until
@@ -501,22 +497,18 @@ impl DutPwrThread {
                 match req {
                     OutputRequest::Idle => {}
                     OutputRequest::On => {
-                        discharge_line
-                            .set_value(1 - DISCHARGE_LINE_ASSERTED)
-                            .unwrap();
-                        pwr_line.set_value(PWR_LINE_ASSERTED).unwrap();
+                        discharge_line.set_value(1 - DISCHARGE_LINE_ASSERTED)?;
+                        pwr_line.set_value(PWR_LINE_ASSERTED)?;
                         state.store(OutputState::On as u8, Ordering::Relaxed);
                     }
                     OutputRequest::Off => {
-                        discharge_line.set_value(DISCHARGE_LINE_ASSERTED).unwrap();
-                        pwr_line.set_value(1 - PWR_LINE_ASSERTED).unwrap();
+                        discharge_line.set_value(DISCHARGE_LINE_ASSERTED)?;
+                        pwr_line.set_value(1 - PWR_LINE_ASSERTED)?;
                         state.store(OutputState::Off as u8, Ordering::Relaxed);
                     }
                     OutputRequest::OffFloating => {
-                        discharge_line
-                            .set_value(1 - DISCHARGE_LINE_ASSERTED)
-                            .unwrap();
-                        pwr_line.set_value(1 - PWR_LINE_ASSERTED).unwrap();
+                        discharge_line.set_value(1 - DISCHARGE_LINE_ASSERTED)?;
+                        pwr_line.set_value(1 - PWR_LINE_ASSERTED)?;
                         state.store(OutputState::OffFloating as u8, Ordering::Relaxed);
                     }
                 }
@@ -528,7 +520,7 @@ impl DutPwrThread {
             Ok(())
         })?;
 
-        let (tick, request, state) = thread_res_rx.next().await.unwrap()?;
+        let (tick, request, state) = thread_rx.recv().await?;
 
         // The request and state topic use the same external path, this way one
         // can e.g. publish "On" to the topic and be sure that the output is