Code review comment for lp:~oif-team/frame/semi-mt-add-touches

Regarding the tracking id range, I think the proper solution is to restrict the id range in the X server, using the exact same semantics as the kernel. The kernel protocol relies on there being a value outside the valid range, and using a different semantics in the X server obviously creates problems.

The original intent with the X tracking id was to mimic the kernel behavior for those kernel drivers with no or poor implementation of kernel tracking ids. Since then, the kernel code for tracking has been centralized, so all type B devices behave exactly the same. Maybe the special handling in X can be dropped now?