When drawing on a tablet, the hand usually rests on the device, causing touch
events. The kernel arbitrates for us in most cases, so we get a touch up
and no events while the stylus is in proximity. When lifting the hand off in a
natural position, the hand still touches the device when the pen goes out of
proximity. This is 'immediately' followed by the hand lifting off the device.

When kernel pen/touch arbitration is active, the pen proximity out causes a
touch begin for the hand still on the pad. This is followed by a touch up when
the hand lifts which happens to look exactly like a tap-to-click.

Fix this by delaying the 'arbitration is now off' toggle, causing any touch
that starts immediately after proximity out to be detected as palm and
ignored for its lifetime.

https://bugs.freedesktop.org/show_bug.cgi?id=104985



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