src/main.rs

@@ -253,7 +253,16 @@ fn run(cfg: &Config, no_touch: bool) -> Result<()> {
     });
 
     if !no_touch {
-        spawn_panel(cfg, tx)?;
+        // Deliberately not fatal. The dashboard is already on the wall by this
+        // point; exiting because the panel is missing would replace a display
+        // you cannot swipe with no display at all. Say so loudly and carry on
+        // serving the control socket, which is still a way to drive it.
+        if let Err(e) = spawn_panel(cfg, tx) {
+            eprintln!("socktop-swipe: touch gestures are NOT active: {e:#}");
+            eprintln!(
+                "socktop-swipe: the dashboard is up; drive it with `socktop-swipe forward` etc."
+            );
+        }
     }
     drive(&tmux, &mut grid, rx)
 }
@@ -281,11 +290,30 @@ fn daemon(cfg: &Config, no_touch: bool) -> Result<()> {
     drive(&tmux, &mut grid, rx)
 }
 
+/// Open the touch panel, retrying briefly.
+///
+/// At boot the autostart can win the race against USB enumeration, so the
+/// device is simply not there yet. Ten seconds covers that without making a
+/// genuinely wrong device path take ten seconds to report.
+fn open_panel(cfg: &Config) -> Result<Touchpanel> {
+    let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+    loop {
+        match Touchpanel::open(&cfg.touch) {
+            Ok(p) => return Ok(p),
+            Err(e) if std::time::Instant::now() < deadline => {
+                std::thread::sleep(std::time::Duration::from_millis(500));
+                let _ = e;
+            }
+            Err(e) => return Err(e),
+        }
+    }
+}
+
 /// Read the panel on its own thread. Opening it here rather than in the thread
 /// keeps a permission or grab failure on the main path, where it can be
 /// reported properly instead of vanishing into a detached thread.
 fn spawn_panel(cfg: &Config, tx: mpsc::Sender<Ctl>) -> Result<()> {
-    let mut panel = Touchpanel::open(&cfg.touch)?;
+    let mut panel = open_panel(cfg)?;
     let gestures = cfg.gestures.clone();
     std::thread::spawn(move || {
         let result = panel.run(|ev| {