new gpr

python_app/hardware_full/librevna_driver/transport/usb.py

@@ -130,7 +130,7 @@ class USBTransport:
             raise DeviceDisconnectedError(f"Failed to prepare USB kernel driver state: {exc}") from exc
 
         try:
-            selected_handle.claimInterface(self.INTERFACE)
+            self._claim_interface_with_busy_recovery(selected_handle)
         except usb1.USBError as exc:
             selected_handle.close()
             if self._ctx is not None:
@@ -152,6 +152,29 @@ class USBTransport:
         self._rx_thread = threading.Thread(target=self._rx_loop, name="librevna-usb-rx", daemon=True)
         self._rx_thread.start()
 
+    def _claim_interface_with_busy_recovery(self, handle: "usb1.USBDeviceHandle") -> None:  # type: ignore[name-defined]
+        """Claim the data interface, clearing a stale BUSY claim once if needed.
+
+        When a previous session's RX thread wedged inside libusb, ``disconnect()``
+        deliberately leaks that handle with the interface still claimed to avoid a
+        use-after-free. A fresh ``connect()`` then fails with
+        ``LIBUSB_ERROR_BUSY``. Resetting the device clears the orphaned claim so
+        the retry succeeds, instead of the device being unusable until it is
+        physically replugged. If the reset forces a re-enumeration the retry raises
+        and the caller falls back to its normal reopen backoff.
+        """
+        try:
+            handle.claimInterface(self.INTERFACE)
+            return
+        except usb1.USBErrorBusy as exc:
+            logger.warning(
+                "USB interface %d busy on claim; resetting device to clear a stale claim: %s",
+                self.INTERFACE,
+                exc,
+            )
+        handle.resetDevice()
+        handle.claimInterface(self.INTERFACE)
+
     def disconnect(self) -> None:
         """Stop RX thread and close USB resources."""
         logger.debug("USB disconnect requested")
@@ -234,8 +257,8 @@ class USBTransport:
                 continue
             except usb1.USBErrorNoDevice as exc:
                 if self._on_disconnect is not None:
-                    self._on_disconnect(DeviceDisconnectedError("USB device disconnected"))
-                logger.warning("USB RX stopped: device disconnected")
+                    self._on_disconnect(DeviceDisconnectedError(f"USB device disconnected: {exc}"))
+                logger.warning("USB RX stopped: device disconnected: %s", exc)
                 return
             except usb1.USBError as exc:
                 if self._stop_event.is_set():