Ubuntu Wiki

This page is for exploring issues encountered with the Lenovo MT hardware. Once we're capable of formulating these into actual tickets/bugs in Launchpad, we will do so.

Touch Area

The first big problem I have noticed with the MT-enabled T410s is that the touch area is not equally sensitive at all points. Using gesturetest to get touch feedback, below I have roughly plotted the responsiveness of light touches across the screen. The "O"s represent a successful touch and the "-"s represent a touch that did not result in any feedback.

Light-pressure Touches

O O O - - - - - - - - - - - - - - - - - - - - 
O O O - - - - - - - - - - - - - - - - O - - -
O - O - O - O - - - - - - - - - - - - - - - -
O - - O O - - - - - - - - - - - - - - - - - -
O O O O - - O - - - - - - - - - - - - - - - -
O O O O - - - - - - - - - - - - - - - - - - - 
O O O O - - - - - - - - - - - - - - - - - O - 
O O O O O O - - O - - - - - - - - - - - - - -  
O O - - O - - - - - - - - - - - - - - - - - - 
O O O - - - - - - - - - - - - - - - - - - O -
O - - - - - - - - - - - - - - - - - O O O O O
O O O - - - - - - - - - - - - - - - O O O O O 

Medium-pressure Touches

O O O O O O O - - - - - - - - - - - - O O O - 
O O O O O O - - - - - - - - - - - - - O - O - 
O O O O - O - - - - O - - - - - - - - - - - - 
O O O - - O - - O - - - O - - - - - - - - - - 
O O O O O O O O O - - - - - - - - - - - - - - 
O O O O O O O O O - - O O O - O - - - O O O O  
O O O O O - - - O O - - - O - - - - - - O - -
O O O O - - - - - - - - - - - - - - - - O - -
O O O - - - - - - - - - - - - - - - - - - - -
O O O O - - - - - - - - - - - - - - - - - - - 
O O O - - - - - - - - - - - - - - - O - O O O
O - - - - - - - - - - - - - - - O O O O O O O

Heavy-pressure Touches

With enough pressure and duration of a gesture, all areas of the screen respond to touch. See conclusions below.

Conclusions

After performing these screen tests and some more experimentation, the following observations were made:

• all areas of the screen will provide a touch response as long as
  • the pressure is great enough (sometimes a lot of pressure is required), and
  • the contact is held long enough
• some areas of the screen just need a quick, light press
• some areas of the screen need to be pressed hard and held for as long as a second
• all areas of the screen responded after one second (with enough pressure applied)
• Windows has a similar issue on the T410s, but it is much, much less noticeable -- it's a mild responsiveness annoyance, rather than a glaring issue
• as such, there is a definite issue in Linux with this particular piece of hardware

Note that a ticket was filed about this issue:

• Work around possible touch hardware issues in Lenovo T410s

• After calibration, the hardware began operating normally and this ticket was marked as invalid.

• Here are instructions for calibrating N-trig-based devices on Linux.