xorg-conf: optimized xorg.conf settings for xf86-input-synaptics on mario mp.

xorg-conf: optimized xorg.conf settings for xf86-input-synaptics on mario mp.

Change-Id: Iffa6acedbe3723001bf335a4b2c8face8402ae6a

BUG=chromium-os:10569
TEST=Slowly move trackpad up to and past top, bottom, right and left edges, and make sure the cursor never 'jumps'.

[tv, 2011-02-22 22:52:35]

http://codereview.chromium.org/6347020/diff/1/chromeos-base/xorg-conf/files/x...
File chromeos-base/xorg-conf/files/xorg.conf-0.0.4 (right):

http://codereview.chromium.org/6347020/diff/1/chromeos-base/xorg-conf/files/x...
chromeos-base/xorg-conf/files/xorg.conf-0.0.4:35: Option    
"EmulateTwoFingerMinZ" "50"
If this behavior is desired, this value seems a little too low to me. I can
trigger the emulation (resulting in a scroll) simply by letting too much of my
finger, or the side of my thumb, onto the pad. I have a big build, but not huge
hands; I can imagine this could cause trouble for people who are notably
overweight, or have a health condition causing hand swelling.

http://codereview.chromium.org/6347020/diff/1/chromeos-base/xorg-conf/files/x...
chromeos-base/xorg-conf/files/xorg.conf-0.0.4:50: Option     "PalmMinWidth" "5"
The palm detection seems to work OK from a few hours of testing, though similar
comments to EmulateTwoFingerMinZ apply here. If I use the flat side of my middle
or ring finger tips, it's really easy to trigger palm-detect (and the pointer
stops dead).

[tv, 2011-02-27 00:39:36]

http://codereview.chromium.org/6347020/diff/1/chromeos-base/xorg-conf/files/x...
File chromeos-base/xorg-conf/files/xorg.conf-0.0.4 (right):

http://codereview.chromium.org/6347020/diff/1/chromeos-base/xorg-conf/files/x...
chromeos-base/xorg-conf/files/xorg.conf-0.0.4:43: Option     "MaxSpeed" "1.9"
This is definitely much more usable than the default of 1.0. Maybe a little too
much on the high end, but of course it's adjustable.

This needs to be coupled with a change to
/opt/google/touchpad/tpcontrol_synclient that provides a different gradient in
maximum speeds (as its highest MaxSpeed is currently still 1.0).