On 07/02/2012 03:07 AM, Henrik Rydberg wrote:

On Thu, Jun 28, 2012 at 03:54:31PM -0400, Yufeng Shen wrote:

quoted

The driver for Apple Magic Trackpad/Mouse currently uses
Multi-touch Protocol A (MT-A) to report touch events and uses
ABS_MT_TRACKING_ID to do finger tracking. The fact of the device
being able to track individual finger makes it possible to
report touch events using MT-B. This patch adds the support
for the driver to report MT-B and makes it configurable through
module parameter so that existing codes that are relying on its
MT-A implemtation don't get affected.

Are there any such codes? Most systems, if not all, seem to use mtdev,
which can handle both protocols. I do not think a parameter switch is
a good idea. Switching to MT-B or leaving things as is look like the
viable options.

Yes, let's just switch to MT-B :). Part of open source is that one can 
look at other implementations to figure out how to make your own new 
device work. We don't want to proliferate MT-A since MT-B is the way 
forward.

In fact, I would also suggest preceding this patch with one that removes 
the switch to turn touch reporting on and off. It's really unnecessary. 
I bet no one in the world turns it off :).

-- Chase