Increase the pressure cutoff for palms

After pressure calibration for the Lulu touchpad, it seems that
the default pressure cutoff for palms of is too low.  May fat
fingers and thumbs register above that value.  Using the newly
calibrated values, I chose a number that seems to work better.

Previously large contacts would sometimes be unable to move the
cursor, which can cause problems for  people with long fingernails
or large fingers when they try to use the touchpad.

This extra-high pressure cutoff is working due to the fact that the
Synaptics TP does its own palm detection (using the full heatmap
and not just area/pressure) and indicates to us when it thinks a
contact is a palm by reporting maximum pressure, which will always
be over this threshold, so it's reasonable to rely on their FW to
determine palm/finger status instead of our naive cutoff.

TEST=manually tested.  With this deployed on the Chromebook it was
quite hard to trigger palm suppression on accident with a thumb or
finger, but my actual palm was stil readily rejected.

Change-Id: I669ba18dccf2203de3e8489465e1daa747115401
Signed-off-by: Charlie Mooney <>
Reviewed-by: Dennis Kempin <>
(cherry picked from commit 9510e64006df8abcccf1053159d4c0fa62843ed8)
1 file changed