[Intel-gfx] Problem with flicker

[Mike Wright]

Hi Intel Graphics Dev team,

I have an really annoying flickering problem.  In MythTV or MPlayer,
pressing skip ahead causes my screen to flicker for about 5-7 seconds
after which time it settles back to a solid image.  This happens about
40% of the time I press skip ahead.  I have taken a video at 60fps of
the problem with my Canon IXUS 50:

http://members.iinet.net.au/~mikewright/TopGear_Flicker.avi    (about 13Mb)

I'm pretty convinced that this has nothing to do with MythTV since
MPlayer does it too.  I'm pretty sure it is not XV either since I'm
think this happens using OpenGL renderer in both players.

I am running:
- Asus P5E-VM using HDMI connected to Pioneer 6th generation plasma TV.
- Ubuntu Jaunty (xserver-xorg-video-intel v2.6.3)
- MythTV 0.21-fixes using XV overlay.
- 1280x720 at 50Hz
- I'm using Yadif de-interlacer.

My guess is that some burst of system load is generated when I skip
video and that causes the Intel (G33) GFX to scan out from a black
buffer every 3 or 4 frames.  Could I be using triple-buffering and be
hitting a GFX Pipe starvation issue?

How do I diagnose this issue???  I'm comfortable building the Intel
drivers from source and have done in the past to chase other issues.
If my assumption is correct then I need to be looking at how the
driver sets up the buffer to scan out from.

Any clues?  WAF is at stake here :-)

Mike