Created attachment 219029 [details] [review]
proposed patch to avoid the issue with touch devices

Both calibration and aspect ratio use the "area" parameter of the device, but on the same hardware, stylus and touch part may not have the same resolution:

    $xsetwacom --get "Wacom Intuos5 touch M Finger touch"  Area
    0 0 4096 4096

    $ xsetwacom --get "Wacom Intuos5 touch M Pen stylus"  Area
    0 0 44704 27940

Therefore applying the area computed on the stylus on the touch device makes it very slow (almost unusable).

The proposed patch avoid applying the area on touch devices, these are normally set to relative mode so aspect ratio does not make sense there either.