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Date: Thu, 19 Jul 2012 09:16:23 -0700
From: Chase Douglas <chase.douglas@canonical.com>
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Subject: Re: [PATCH v2] Input: synaptics - use firmware data for Cr-48
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On 07/18/2012 08:02 PM, Chung-Yih Wang (王崇懿) wrote:
> Hi Chase,
>
>     Thanks for your great comments. You are right, it is impossible to
> get  correct finger tracking if both fingers are moving. However, we
> think it still worth to have the firmware tracking of the fingers as
> they could perform well for most one-stationary-one-moving cases. This
> will be good enough for the one-stationary-one-moving gestures we want
> to provide on Cr-48. And that's why we want to make the patch specific
> to Cr-48.

Can you provide more details on what you are attempting to accomplish? 
The only thing you can't do easily with semi-mt is:

* Rotations (but the hardware can't do it anyway, so this is moot)
* Pinch directions at 45 degree angles (i.e. (pinch up and left, down 
and right) or (pinch down and left, up and right))

You should be able to do everything else with semi-mt, such as pinch 
horizontally vs pinch vertically, movement, etc.

The pinch directions at 45 degree angles could be possible with the 
Cr-48 trackpad, but I would want to know that there's a real use case 
for it before undertaking an effort to support it.

-- Chase