fix(evdev): strip SW_RFKILL_ALL from uinput clone capabilities (#947)

The evdev uinput clone copied EV_SW capabilities verbatim. "ThinkPad Extra Buttons" (thinkpad_acpi) declares SW_RFKILL_ALL, and a fresh uinput device reports every switch as 0. The kernel rfkill-input handler reads a 0 killswitch as radios-off, so every clone creation soft-blocked all radios at startup and again after every resume.

Strip SW_RFKILL_ALL from the clone capability list, dropping EV_SW entirely when it was the only switch. Other switches stay declared so real switch events still forward; a forwarded SW_RFKILL_ALL write is dropped by the kernel for the undeclared code.

Fixes #946

src/vocalinux/ui/keyboard_backends/evdev_backend.py

@@ -1317,6 +1317,14 @@ class EvdevDeviceHub:
         EV_REP is filtered out so the clone never autorepeats: the physical
         device's own repeat events are forwarded verbatim, preserving its
         repeat rate without doubling repeats.
+
+        SW_RFKILL_ALL is stripped from EV_SW: a fresh uinput device reports
+        every switch as 0, and the kernel's rfkill-input handler reads a 0
+        killswitch as radios-off — cloning that bit soft-blocks all radios
+        the moment the clone appears, on ThinkPads and any other device
+        declaring it (#946). The clone keeps every other switch so real
+        switch events still forward; a forwarded SW_RFKILL_ALL write is
+        dropped by the kernel for the undeclared code.
         """
         try:
             capabilities: dict[int, Sequence[int]] = {
@@ -1324,6 +1332,13 @@ class EvdevDeviceHub:
             }
             for event_type in (ecodes.EV_SYN, ecodes.EV_FF, ecodes.EV_REP):
                 capabilities.pop(event_type, None)
+            switches = [
+                code for code in capabilities.get(ecodes.EV_SW, ()) if code != ecodes.SW_RFKILL_ALL
+            ]
+            if switches:
+                capabilities[ecodes.EV_SW] = switches
+            else:
+                capabilities.pop(ecodes.EV_SW, None)
             name = _clone_device_name(device)
             try:
                 return UInput(

tests/test_evdev_backend_ext.py

@@ -1362,6 +1362,69 @@ class TestEvdevGrabAndForwarding:
         assert backend._forwarders[10] is forwarder
         assert device in backend.devices
 
+    @patch("vocalinux.ui.keyboard_backends.evdev_backend.UInput")
+    @patch("vocalinux.ui.keyboard_backends.evdev_backend.InputDevice")
+    def test_clone_drops_rfkill_switch_keeps_other_switches(
+        self, mock_input_device: Mock, mock_uinput: Mock
+    ) -> None:
+        """The clone must not declare SW_RFKILL_ALL (#946).
+
+        "ThinkPad Extra Buttons" declares SW_RFKILL_ALL. A fresh uinput
+        device reports every switch as 0, and the kernel's rfkill-input
+        handler reads a 0 killswitch as radios-off — cloning the bit
+        soft-blocked all radios on every startup and resume. Other
+        switches stay declared so real switch events still forward.
+        """
+        device = MagicMock()
+        device.fileno.return_value = 10
+        device.active_keys.return_value = []
+        device.capabilities.return_value = {
+            ecodes.EV_KEY: [30],  # KEY_A
+            ecodes.EV_SW: [ecodes.SW_RFKILL_ALL, ecodes.SW_TABLET_MODE],
+        }
+        mock_input_device.return_value = device
+        forwarder = MagicMock()
+        forwarder.device.path = "/dev/input/event20"
+        mock_uinput.return_value = forwarder
+
+        backend = EvdevKeyboardBackend()
+        opened = backend._open_keyboard_device("/dev/input/event0")
+
+        assert opened is True
+        events = mock_uinput.call_args.kwargs["events"]
+        assert ecodes.SW_RFKILL_ALL not in events[ecodes.EV_SW]
+        assert ecodes.SW_TABLET_MODE in events[ecodes.EV_SW]
+
+    @patch("vocalinux.ui.keyboard_backends.evdev_backend.UInput")
+    @patch("vocalinux.ui.keyboard_backends.evdev_backend.InputDevice")
+    def test_clone_drops_ev_sw_when_only_switch_is_rfkill(
+        self, mock_input_device: Mock, mock_uinput: Mock
+    ) -> None:
+        """A device declaring only SW_RFKILL_ALL gets no EV_SW at all (#946).
+
+        ThinkPad Extra Buttons reports SW=8: bit 3 alone. Declaring an
+        empty EV_SW capability would still register a switch device, so
+        the type is dropped entirely.
+        """
+        device = MagicMock()
+        device.fileno.return_value = 10
+        device.active_keys.return_value = []
+        device.capabilities.return_value = {
+            ecodes.EV_KEY: [30],  # KEY_A
+            ecodes.EV_SW: [ecodes.SW_RFKILL_ALL],
+        }
+        mock_input_device.return_value = device
+        forwarder = MagicMock()
+        forwarder.device.path = "/dev/input/event20"
+        mock_uinput.return_value = forwarder
+
+        backend = EvdevKeyboardBackend()
+        opened = backend._open_keyboard_device("/dev/input/event0")
+
+        assert opened is True
+        events = mock_uinput.call_args.kwargs["events"]
+        assert ecodes.EV_SW not in events
+
     @patch("vocalinux.ui.keyboard_backends.evdev_backend.UInput")
     @patch("vocalinux.ui.keyboard_backends.evdev_backend.InputDevice")
     @patch("vocalinux.ui.keyboard_backends.evdev_backend.os.path.exists")