LightDM GTK+ Greeter Background - inconsistent display


Tested HW:

- Family : NV50
  Chipset: G98 (NV98) / MCP79/MCP7A (NVAC)
      GeForce 8400 GS / ION VGA

nouveau.ko & nouveau_drv.so     - BROKEN
nouveau.ko & modesetting_drv.so - OK
nvidia.ko & nvidia_drv.so       - OK
~~~~~~~~~~~~~~

- Family : NV30
  Chipset: NV34 (NV34)
       GeForce FX 5200

nouveau.ko & nouveau_drv.so     - OK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Tested SW:

- lightdm-gtk-2.0.0-2.fc21.x86_64
- lightdm-gtk-greeter_2.0.0-0ubuntu1_amd64
- xorg-x11-drv-nouveau 1.0.7 to 1.0.11 & git

~~~~~~~~~~~~~~

As shown here:
http://goo.gl/jHUkbS

~~~~~~~~

Comment:
Whatever is actually happening here is not evident in the logs:
dmesg, Xorg.*.log, lightdm.log(DEBUG) and x-*-greeter.log(DEBUG).

Top of the "greeter.png"
/etc/lightdm/lightdm-gtk-greeter.conf:
background=/etc/lightdm/greeter.png

is partially visible through the transparent panel:
https://github.com/shimmerproject/Greybird/blob/master/gtk-3.0/apps/lightdm-gtk-greeter.css#L14

and is fully revealed only after clicking the "Log In" or "Unlock" button
(ENTER key), 
or toggling the accessibility features such as "Large Font" (F1 key) and "High
Contrast" (F2 key).

It is important to note the Greeter Background display inconsistency occurs
entirely after the booting from the "Soft Off" (S5).
And with regard to the re-booting, it is unpredictable in itself, i.e. the
Greeter Background may be displayed or may not.



Ref.
http://lists.freedesktop.org/archives/lightdm/2015-March/000773.html