Michel Dänzer authored Dec 22, 2017 and Michel Dänzer committed Dec 27, 2017

And use this to determine when we cannot use page flipping for DRI
clients. We previously did this based on whether the HW cursor cannot
be used on at least one CRTC, which had at least two issues:

* Even while the HW cursor cannot be used, no SW cursor may actually be
  visible (e.g. because all cursors are disabled), in which case we can
  use page flipping for DRI clients anyway
* Even while the HW cursor can be used, there may be SW cursors visible
  from non-core pointer devices, in which case we cannot use page
  flipping for DRI clients anyway

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>