When dissociating a universal plane from a crtc, we currently don't
reset the current state of the plane (plane->state_cur). When attempting
to use this plane in the future, we can run into invalid memory accesses
due to left over associations with potentially freed drm backend
objects. This commit resets the state of the scanout and cursor
universal planes associated with a crtc.
The following scenario exhibits the problem:
1. Start a (fullscreen) client that is suitable for and assigned to
the scanout plane. The plane's state_cur->output value is set.
2. Unplug the monitor: the scanout plane is "released" but still
maintains the state_cur->output association.
3. Replug the monitor: the plane is deemed unavailable due to an
existing, albeit invalid, state_cur->output value. Note the memory
errors trying to access the drm_output which was freed at step (2).
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Alexandros Frantzis
53a71cb186