[Precise][SRU][pull-request] Cypress PS/2 Trackpad updates

[git at status.e4ward.com]

Bug references:
	https://bugs.launchpad.net/dell-sputnik/+bug/1055788
	XPS 13 touchpad: Quickly clicking touchpad results in double click (with tap to click)

	https://bugs.launchpad.net/dell-sputnik/+bug/1048258
	Cypress trackpad gets psmouse lost sync / driver resynced warnings

	https://bugs.launchpad.net/dell-sputnik/+bug/1064086
	Cypress trackpad: Occasional taps leak through as clicks even with tap-to-click disabled

[IMPACT]

This patch fixes a number of issues with the new Cypress PS/2 Trackpad driver.
The first issue is that xserver-xorg-input-synaptics misinterprets a quick hardware
click as a double click when tap-to-click is enabled (one click from the tap,
one click from the hardware click). The second issue is that the trackpad loses
synchronization upon palm contact. The last issue is that, even with tap-to-click
disabled, occasional taps get interpreted as clicks.

[TESTCASE]

1. Enable tap-to-click in Mouse and Touchpad settings.
2. $ xev | grep Button
3. Tap the touchpad anywhere except the mouse buton zones
   with enough pressure to cause a hardware click, but release
   fast enough to register as a tap to X. Notice two sets of
   button presses and releases.
4. Disable tap-to-click in Mouse and Touchpad settings.
5. $ tail -f /var/log/kern.log
6. Touch palm to trackpad. Notice lost sync/resync messages.
7. Remove palm. Notice no more lost sync/resync messages.
8. Repeatedly tap (don't depress clickpad) on the bottom edge/corners
   of the trackpad. Notice the occasional click.
9. Test 1-8 with patch applied. With tap-to-click enabled, observe
   only a single set of button presses and releases. With tap-to-click
   disabled, observe no more occasional taps turning into clicks.
   Finally, notice no more lost sync/resync messages upon palm contact.

[Regression Potential]

None known. This patch affects only the Cypress PS/2 Trackpad driver.

----------

The following changes since commit 61e43e85719ed35bd64d4e4b1d0cb963ab3fec87:

  au0828: fix case where STREAMOFF being called on stopped stream causes BUG() (2012-10-11 14:12:18 -0600)

are available in the git repository at:

  git://kernel.ubuntu.com/kamal/ubuntu-precise.git cypress-update

for you to fetch changes up to b2d5246bf9ba033751692494358d49938e017d9b:

  UBUNTU: SAUCE: input: Cypress PS/2 Trackpad list additional contributors (2012-10-15 10:57:53 -0700)

----------------------------------------------------------------
Kamal Mostafa (1):
      UBUNTU: SAUCE: input: Cypress PS/2 Trackpad list additional contributors

Kyle Fazzari (3):
      UBUNTU: SAUCE: input: Cypress PS/2 Trackpad fix multi-source, double-click
      UBUNTU: SAUCE: input: Cypress PS/2 Trackpad fix lost sync upon palm contact
      UBUNTU: SAUCE: input: Cypress PS/2 Trackpad fix taps turning into hardware clicks

 drivers/input/mouse/cypress_ps2.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)