From 140eef551396947ef44978feadf056df39ddf0b1 Mon Sep 17 00:00:00 2001
From: Brad Stein <brad.stein@gmail.com>
Date: Wed, 25 Jun 2025 23:27:51 -0500
Subject: [PATCH] server udc fix

---
 server/src/main.rs       |  2 +-
 server/src/usb_gadget.rs | 25 ++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/server/src/main.rs b/server/src/main.rs
index a4020ee..b40d6dc 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -51,7 +51,7 @@ fn init_tracing() -> anyhow::Result<WorkerGuard> {
 }
 
 async fn open_with_retry(path: &str) -> anyhow::Result<tokio::fs::File> {
-    const MAX_ATTEMPTS: usize = 40;      // ≈ 2 s (@50 ms)
+    const MAX_ATTEMPTS: usize = 200;      // ≈ 10 s (@50 ms)
     for attempt in 1..=MAX_ATTEMPTS {
         match OpenOptions::new()
             .write(true)
diff --git a/server/src/usb_gadget.rs b/server/src/usb_gadget.rs
index dec0dd9..7188838 100644
--- a/server/src/usb_gadget.rs
+++ b/server/src/usb_gadget.rs
@@ -84,7 +84,30 @@ impl UsbGadget {
         /* 3 – re‑attach gadget */
         info!("🔌 re‑attaching gadget to {ctrl}");
         Self::write_attr(self.udc_file, &ctrl)?;
-        Self::wait_state(&ctrl, "configured", 6_000)?;
+
+        /* 4 – toggle gadget */
+        let sc = format!("/sys/class/udc/{ctrl}/soft_connect");
+        // toggle 0 → 1 to force the controller to assert pull‑ups
+        Self::write_attr(&sc, "0")?;                         // guarantee clean edge
+        thread::sleep(Duration::from_millis(50));
+        Self::write_attr(&sc, "1")?;
+
+        /* 4 – wait for gadget */
+        Self::wait_state(&ctrl, "configured", 6_000)
+            .or_else(|e| {
+                // If the host is physically absent (sleep / KVM paused)
+                // we allow 'not attached' and continue – we can still
+                // accept keyboard/mouse data and the host will enumerate
+                // later without another reset.
+                let last = fs::read_to_string(format!("/sys/class/udc/{ctrl}/state"))
+                    .unwrap_or_default();
+                if last.trim() == "not attached" {
+                    warn!("⚠️ host did not enumerate within 6 s – continuing (state = {last:?})");
+                    Ok(())
+                } else {
+                    Err(e)
+                }
+            })?;
 
         info!("✅ USB‑gadget cycle complete");
         Ok(())