Unsynced TMDS with xf86-video-intel on 945GM

René Rebe rene at exactcode.de
Wed May 16 00:55:49 PDT 2007

On Monday 14 May 2007 09:18:51 you wrote:
> Hi all,
> it appears there is one problem left with xf86-video-intel 2.0.0 on the 945GM
> (as inside the Apple MacBook r2), I use this sniplett to change to a DVI
> connected Apple Cinema Display on X start (.xinitrc):
> if xrandr | grep -q 'TMDS-1 connected'; then
>         xrandr  --output TMDS-1  --preferred
>         xrandr --output LVDS --off
> fi
> However often (like about 80% of the X starts) I get flickering and rolling thru
> pixel trash on the external display. It "looks" like there is some sync (or so)
> missing or imprecise, as it's the actual desktop pixel content flushing and
> shuffling by.
> Interesting is that when I rotate the desktop cube (of Beryl) the image get's
> in sync, and when the Beryl "rotate cube" mode is left the display content
> is unsynced again (rolling and flickering by).
> This can be fixed by re-enabling the LVDS and disabling it again:
> xrandr --output LVDS --auto
> xrandr --output LVDS --off
> Though sometimes even this only worked on the third attempt.
> Once this sequence made the DVI "be synced"(?), it works for
> infinite hours, like whole weeks, until one restarts X or resumes
> from suspend-to-ram.
> Any idea?

I have an interesting, new data-point. Since I had some lost window
decoration hanging on the screen I killed beryl away to restart it:

killall beryl ; beryl

Which immediatly gave me randomly shifting pixel garbage back
on screen !!!

So this problem appears to not be the TMDS output but the 3D
engine causing strange random pixel shifting that can be healed
by reprogramming the outputs?

/me confused

xf86-video-i810 2.0.0
mesa 6.5.2
linux26 2.6.21

  René Rebe - ExactCODE GmbH - Europe, Germany, Berlin
  http://exactcode.de | http://t2-project.org | http://rene.rebe.name

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