touchpad: if we have a right button, let's assume it's not a clickpad

This assumption dates back roughly a decade when INPUT_PROP_BUTTONPAD was
introduced into the kernel. To my knowledge, devices right now erroneously
advertise INPUT_PROP_BUTTONPAD when they are not a clickpad (but then they
have BTN_RIGHT) or they lack INPUT_PROP_BUTTONPAD (and only have BTN_LEFT).

So let's change our assumption here - if a clickpad has a right button log the
kernel bug and continue with the assumption the device is a touchpad with
physical buttons.

To disable that warning, fix the kernel or add an AttrInputPropDisable quirk
for the device.

Fixes #595

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

2 files changed, 32 insertions, 14 deletions

diff --git a/src/evdev-mt-touchpad-buttons.c b/src/evdev-mt-touchpad-buttons.c
index be399bc7..8ce1e13c 100644
--- a/src/evdev-mt-touchpad-buttons.c
+++ b/src/evdev-mt-touchpad-buttons.c
@@ -940,7 +940,6 @@ tp_guess_clickpad(const struct tp_dispatch *tp, struct evdev_device *device)
 {
 	bool is_clickpad;
 	bool has_left = libevdev_has_event_code(device->evdev, EV_KEY, BTN_LEFT),
-	     has_middle = libevdev_has_event_code(device->evdev, EV_KEY, BTN_MIDDLE),
 	     has_right = libevdev_has_event_code(device->evdev, EV_KEY, BTN_RIGHT);
 
 	is_clickpad = libevdev_has_property(device->evdev, INPUT_PROP_BUTTONPAD);
@@ -952,24 +951,19 @@ tp_guess_clickpad(const struct tp_dispatch *tp, struct evdev_device *device)
 	 *   single physical button
 	 * - Wacom touch devices have neither left nor right buttons
 	 */
-	if (!is_clickpad && has_left && !has_right &&
-	    (tp->device->model_flags & EVDEV_MODEL_APPLE_TOUCHPAD_ONEBUTTON) == 0) {
+	if (is_clickpad) {
+		if (has_right) {
+			evdev_log_bug_kernel(device,
+					     "clickpad with right button, assuming it is not a clickpad\n");
+			is_clickpad = false;
+		}
+	} else if (has_left && !has_right &&
+		   (tp->device->model_flags & EVDEV_MODEL_APPLE_TOUCHPAD_ONEBUTTON) == 0) {
 		evdev_log_bug_kernel(device,
 				     "missing right button, assuming it is a clickpad.\n");
 		is_clickpad = true;
 	}
 
-	if (has_middle || has_right) {
-		if (is_clickpad)
-			evdev_log_bug_kernel(device,
-					     "clickpad advertising right button\n");
-	} else if (has_left &
-		   !is_clickpad &&
-		   libevdev_get_id_vendor(device->evdev) != VENDOR_ID_APPLE) {
-			evdev_log_bug_kernel(device,
-					     "non clickpad without right button?\n");
-	}
-
 	return is_clickpad;
 }
 
diff --git a/test/test-touchpad-buttons.c b/test/test-touchpad-buttons.c
index 6af571d9..e55da5c1 100644
--- a/test/test-touchpad-buttons.c
+++ b/test/test-touchpad-buttons.c
@@ -2098,6 +2098,29 @@ START_TEST(touchpad_non_clickpad_detection)
 }
 END_TEST
 
+START_TEST(touchpad_clickpad_detection)
+{
+	struct litest_device *dev;
+	uint32_t methods;
+	int codes[] = {
+		INPUT_PROP_MAX, INPUT_PROP_BUTTONPAD,
+		-1, -1,
+	};
+
+	/* Create a device with LR buttons and INPUT_PROP_BUTTONPAD set - we
+	 * should ignore the property and assume it's a non-clickpad.
+	 * Only way to check that is to verify no click methods are set.
+	 */
+	dev = litest_create_device_with_overrides(LITEST_SYNAPTICS_TOUCHPAD,
+						  "litest Fake Clickpad",
+						  NULL, NULL, codes);
+
+	methods = libinput_device_config_click_get_methods(dev->libinput_device);
+	ck_assert(methods == 0);
+	litest_delete_device(dev);
+}
+END_TEST
+
 TEST_COLLECTION(touchpad_buttons)
 {
 	struct range finger_count = {1, 4};
@@ -2168,5 +2191,6 @@ TEST_COLLECTION(touchpad_buttons)
 	litest_add(clickpad_middleemulation_click_enable_while_down, LITEST_CLICKPAD, LITEST_ANY);
 	litest_add(clickpad_middleemulation_click_disable_while_down, LITEST_CLICKPAD, LITEST_ANY);
 
+	litest_add_no_device(touchpad_clickpad_detection);
 	litest_add_no_device(touchpad_non_clickpad_detection);
 }