[PATCH 3/3] Input: synaptics - remove touches over button click area

[Chris Bagwell]

On 10/08/2010 09:58 AM, Chase Douglas wrote:
> Now that we have proper multitouch support, we can handle integrated
> buttons better. If we know the top of the buttons on the touchpad, we
> can ignore any touches that occur within the touchpad area while a
> button is clicked. It may be possible to get the button area by querying
> the device, but for now allow the user to manually set it.
>
> A note on why this works: the Synaptics touchpads have pseudo touch
> tracking. When two touches are on the touchpad, an MT touch packet with
> just the X, Y, and pressure values is sent before a normal Synaptics
> touch packet. When one touch is obviously in motion and the other is
> stationary, the touchpad controller sends the touch in motion in the
> normal packet and the stationary touch in the MT packet. Single touch
> emulation is provided by the normal packet, so an action like clicking
> a button and dragging with another finger still works as expected.
>
> Tested on a Dell Mini 1012 with synaptics_multitouch=1 and
> synaptics_button_thresh=4100.
>

Even if we did not submit the MT logic, I'd go a totally different 
direction and move clickpad button press support fully to 
xf86-input-synaptics and I'd remove the logic from kernel side that maps 
HW's middle button to left button.  It seems just limping a long with 
single button support anyways.

I haven't had time to review Takashi's xf86-input-synaptics patches just 
sent yet but seems along this line of thinking as well.

Chris