xf86-video-intel 1.9.94: (WW) intel(0): Hardware claims plane A is off while software believes it is on

[Barry Scott]

I'm testing Xorg 7.2 + updated modules needed to support intel 1.9.94
running on 2.6.20 linux kernel with its drm drivers.

I'm not seeing anything on the screen, the LCD has gone into screen 
saver mode.
However apps are happy running and I can get a screen snap shot that shows
what I expect on the screen.

How can I help debug this situation?

The config and full log are available here:

http://www.onelan.co.uk/xorg-tmp/945.conf
http://www.onelan.co.uk/xorg-tmp/xserver-945.log

Here are some messages that may be related to the problem:

(EE) intel(0): I830 Vblank Pipe Setup Failed 0

(II) intel(0): Attempting memory allocation with tiled buffers and
               large DRI memory manager reservation:
(WW) intel(0): xf86AllocateGARTMemory: allocation of 10 pages failed
        (Cannot allocate memory)

I'm guessing that the (WW) is very at the heart of the problem.

(II) intel(0): Output configuration:
(II) intel(0):   Pipe A is on
(II) intel(0):   Display plane A is now enabled and connected to pipe A.
(WW) intel(0):   Hardware claims plane A is off while software believes 
it is on
(II) intel(0):   Pipe B is off
(II) intel(0):   Display plane B is now disabled and connected to pipe B.
(II) intel(0):   Output VGA is connected to pipe none

I'm still using the config that I generate for a 7.1 system, I've not 
got my head around
the new config yet, in case that matters.

Barry