[PATCH xf86-input-libinput] Only init abs axes if we don't have acceleration

[Peter Hutterer]

A lot of devices (mainly MS input devices) have abs axes on top of the
relative axes. Those axes are usually mute but with the current code we set up
absolute axes for those devices. Relative events are then scaled by the server
which makes the device appear slow.

As an immediate fix always prefer relative axes and only set up absolute axes
if the device has a calibration matrix but no pointer acceleration.
This may mess up other devices where the relative axes are dead, we'll deal
with this when it comes.

https://bugs.freedesktop.org/show_bug.cgi?id=90322

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
Long term we need to look at splitting a second xorg device out if we get
events from an interface that we didn't expect. Let's deal with that when we
have to.

 src/libinput.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/libinput.c b/src/libinput.c
index 1b84e21..3cc4426 100644
--- a/src/libinput.c
+++ b/src/libinput.c
@@ -91,6 +91,8 @@ struct xf86libinput {
 		double y_remainder;
 	} scale;
 
+	BOOL has_abs;
+
 	ValuatorMask *valuators;
 	ValuatorMask *valuators_unaccelerated;
 
@@ -533,6 +535,8 @@ xf86libinput_init_pointer_absolute(InputInfoPtr pInfo)
 	SetScrollValuator(dev, 2, SCROLL_TYPE_HORIZONTAL, driver_data->scroll.hdist, 0);
 	SetScrollValuator(dev, 3, SCROLL_TYPE_VERTICAL, driver_data->scroll.vdist, 0);
 
+	driver_data->has_abs = TRUE;
+
 	return Success;
 }
 static void
@@ -643,7 +647,8 @@ xf86libinput_init(DeviceIntPtr dev)
 	if (libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_KEYBOARD))
 		xf86libinput_init_keyboard(pInfo);
 	if (libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_POINTER)) {
-		if (libinput_device_config_calibration_has_matrix(device))
+		if (libinput_device_config_calibration_has_matrix(device) &&
+		    !libinput_device_config_accel_is_available(device))
 			xf86libinput_init_pointer_absolute(pInfo);
 		else
 			xf86libinput_init_pointer(pInfo);
@@ -728,6 +733,13 @@ xf86libinput_handle_absmotion(InputInfoPtr pInfo, struct libinput_event_pointer
 	ValuatorMask *mask = driver_data->valuators;
 	double x, y;
 
+	if (!driver_data->has_abs) {
+		xf86IDrvMsg(pInfo, X_ERROR,
+			    "Discarding absolute event from relative device. "
+			    "Please file a bug\n");
+		return;
+	}
+
 	x = libinput_event_pointer_get_absolute_x_transformed(event, TOUCH_AXIS_MAX);
 	y = libinput_event_pointer_get_absolute_y_transformed(event, TOUCH_AXIS_MAX);
 
-- 
2.3.5