usbhubd: trace SetPortReset result + wait_for_reset boundaries (diagnostic)

Log SetPortFeature(PORT_RESET) result, wait_for_reset's first fetch,
and its completion/timeout outcomes at info level to pinpoint where
hub port-reset polling stalls in QEMU.

drivers/usb/usbhubd/src/main.rs

@@ -578,9 +578,12 @@ fn main() {
             // then 50ms TRSTRCY recovery and C_PORT_RESET clear.
             if !snap.enabled {
                 log::info!("reset port {port}");
-                if let Err(e) = set_feature(&handle, port, usb::HubPortFeature::PortReset) {
-                    log::warn!("usbhubd: SetPortReset failed for port {}: {}", port, e);
-                    continue;
+                match set_feature(&handle, port, usb::HubPortFeature::PortReset) {
+                    Ok(()) => log::info!("HUBFLOW {port}: PortReset set ok"),
+                    Err(e) => {
+                        log::warn!("usbhubd: SetPortReset failed for port {}: {}", port, e);
+                        continue;
+                    }
                 }
                 state.ensure_attached(false);
                 if let Err(e) = port_ops::wait_for_reset(

drivers/usb/usbhubd/src/port_ops.rs

@@ -183,18 +183,21 @@ pub fn wait_for_reset<E>(
     let mut delay = HUB_SHORT_RESET_TIME_MS;
 
     let mut cur = fetch().map_err(WaitError::Io)?;
+    log::info!("HUBFLOW wait_for_reset: first fetch resetting={} connected={}", cur.resetting, cur.connected);
     loop {
         if !cur.resetting && cur.connected {
             sleep(RESET_RECOVERY_TIME_MS);
             if cur.reset_changed {
                 clear_reset_change().map_err(WaitError::Io)?;
             }
+            log::info!("HUBFLOW wait_for_reset: complete after {}ms", total_ms);
             return Ok(cur);
         }
         if !cur.connected {
             return Err(WaitError::Disconnected);
         }
         if total_ms >= HUB_RESET_TIMEOUT_MS {
+            log::info!("HUBFLOW wait_for_reset: timeout, still resetting={}", cur.resetting);
             return Err(WaitError::Timeout);
         }
         sleep(delay);