[sfputil] Add generic function to get lane mask by given subport and …

…lane count

Signed-off-by: xinyu <xinyu0123@gmail.com>

sfputil/main.py

@@ -2032,9 +2032,9 @@ def loopback(port_name, loopback_mode, enable):
  sys.exit(EXIT_FAIL)
 
  if 'host-side' in loopback_mode:
- lane_mask = ((1 << host_lane_count) - 1) << ((subport - 1) * host_lane_count)
+ lane_mask = get_subport_lane_mask(subport, host_lane_count)
  elif 'media-side' in loopback_mode:
- lane_mask = ((1 << media_lane_count) - 1) << ((subport - 1) * media_lane_count)
+ lane_mask = get_subport_lane_mask(subport, media_lane_count)
  else:
  lane_mask = 0
 
@@ -2055,5 +2055,19 @@ def loopback(port_name, loopback_mode, enable):
  click.echo("{}: Set {} loopback failed".format(port_name, loopback_mode))
  sys.exit(EXIT_FAIL)
 
+
+def get_subport_lane_mask(subport, lane_count):
+ """Get the lane mask for the given subport and lane count
+
+ Args:
+ subport (int): Subport number
+ lane_count (int): Lane count for the subport
+
+ Returns:
+ int: Lane mask for the given subport and lane count
+ """
+ return ((1 << lane_count) - 1) << ((subport - 1) * lane_count)
+
+
 if __name__ == '__main__':
  cli()

tests/sfputil_test.py

@@ -1709,3 +1709,14 @@ def test_debug_loopback(self, mock_sonic_v2_connector, mock_config_db_connector,
  ["Ethernet0", "media-side-input", "enable"])
  assert result.output == 'Ethernet0: Failed to connect to STATE_DB\n'
  assert result.exit_code == EXIT_FAIL
+
+ @pytest.mark.parametrize("subport, lane_count, expected_mask", [
+ (1, 1, 0b1),
+ (1, 4, 0b1111),
+ (2, 1, 0b10),
+ (2, 4, 0b11110000),
+ (3, 2, 0b1100),
+ (4, 1, 0b1000),
+ ])
+ def test_get_subport_lane_mask(subport, lane_count, expected_mask):
+ assert get_subport_lane_mask(subport, lane_count) == expected_mask