Re: [PATCH 6/9 v2] Input: synaptics - process finger (<=3) transitions

From: Chase Douglas
Date: Fri Jul 22 2011 - 21:11:47 EST

On 07/20/2011 06:39 AM, djkurtz@xxxxxxxxxxxx wrote:
> From: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> Synaptics image sensor touchpads track 5 fingers, but only report 2.
> This patch attempts to deal with some idiosyncrasies of these touchpads:
> * When there are 3 or more fingers, only two are reported.
> * The number of fingers can change at any time, but is only reported in
> SGM packets, thus at a number-of-fingers change, it is not possible
> to tell whether the AGM finger is for the original or new number of
> fingers.
> * When the number of fingers changes from 2->3 it is not
> possible to tell which of the 2 fingers are now reported.
> * When number of fingers changes from 3->2 it is often not possible to
> tell which finger was removed, and which are now being reported.
> When 2 or more packets are present on the touchpad, the kernel reports
^touches or fingers
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