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

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.

Thanks,
Henrik