Merge pull request #1334 from joergho/usbserial-suggest-interface-num

resource: udev: also suggest ID_USB_INTERFACE_NUM for USBResource

Author: Emantor

doc/configuration.rst

@@ -109,12 +109,15 @@ This allows identification through hot-plugging or rebooting.
    USBSerialPort:
      match:
        ID_SERIAL_SHORT: 'P-00-00682'
+       ID_USB_INTERFACE_NUM: '00'
      speed: 115200
 
-The example would search for a USB serial converter with the key
-``ID_SERIAL_SHORT`` and the value ``P-00-00682`` and use it with a baud rate
-of ``115200``.
-The ``ID_SERIAL_SHORT`` property is set by the ``usb_id`` builtin helper program.
+The example would search for a USB serial converter with a given serial number
+(``ID_SERIAL_SHORT`` = ``P-00-00682``) and use first interface
+(``ID_USB_INTERFACE_NUM`` = ``00``) with a baud rate of 115200.
+
+The ``ID_SERIAL_SHORT`` and ``ID_USB_INTERFACE_NUM`` properties are set by the
+``usb_id`` builtin helper program.
 
 Arguments:
   - match (dict): key and value pairs for a udev match, see `udev Matching`_

labgrid/resource/udev.py

@@ -91,12 +91,22 @@ def suggest_match(self, device):
                 suggestions.append({'@ID_PATH': path})
 
         serial = self.device.properties.get('ID_SERIAL_SHORT')
+        interface_num = self.device.properties.get('ID_USB_INTERFACE_NUM')
         if serial:
-            suggestions.append({'ID_SERIAL_SHORT': serial})
+            if interface_num is not None:
+                suggestions.append({'ID_SERIAL_SHORT': serial,
+                                    'ID_USB_INTERFACE_NUM': interface_num})
+            else:
+                suggestions.append({'ID_SERIAL_SHORT': serial})
         elif self.match.get('@SUBSYSTEM', None) == 'usb':
             serial = self._get_usb_device().properties.get('ID_SERIAL_SHORT')
+            interface_num = self._get_usb_device().properties.get('ID_USB_INTERFACE_NUM')
             if serial:
-                suggestions.append({'@ID_SERIAL_SHORT': serial})
+                if interface_num is not None:
+                    suggestions.append({'@ID_SERIAL_SHORT': serial,
+                                        '@ID_USB_INTERFACE_NUM': interface_num})
+                else:
+                    suggestions.append({'@ID_SERIAL_SHORT': serial})
 
         return meta, suggestions