Output disappearing with intel driver

[alan c]

Erik Nilsson wrote:
> Hi there! 
> 
> I've run into some strange behaviour with my laptop with an intel G945
> graphics controller.
> 
> First it worked fine with my external monitor (connected with DVI), then
> I tried it without it attached - worked fine - then reattached - bummer
> no picture on the external display. 
> 
> I've tried to troubleshoot it and the problem seem to be that xrandr (or
> even deeper down: the intel driver) isn't detecting and TMDS-1 output
> anymore. That is, it's just not failing to detect that it is connected,
> i doesn't even show up when I run the xrandr command.
> 
> This is all on Ubuntu Hardy Heron (and, no it didn't stop working with
> the upgrade, it happened later on).

(I am not a developer and am new to the list)

I am finding that with my laptop (note1) I get unpredictable problems 
with the display not appearing at startup sometimes, or on restart of 
xserver. This is most obvious with Hardy Heron Live CD, also Hardy 
Heron installed (updated to date), and also with the recent knoppix 
dvd 5.3.1

With Hardy Heron (seems to use i915_dri.so) a normal display appears 
about 6 times out of 10. With Knoppix 5.3.1 a normal display appears 
about 9 times out of 10 (seems to use i915_dri.so, calls driver i810 
in xorg.conf)

When a black screen appears instead, it is often possible to gain or 
regain a normal display with various use of ctrl alt backspace, maybe 
ctrl alt F1 (or F2) and ctrl alt F7 (F5 for knoppix). I have not found 
a systematic procedure yet for this.

After a good boot up with display showing ok, if ctrl alt backspace is 
used, then again there is unpredictable chance of good display re 
appearing.

Note1: Dell Inspiron 1100 which is a beast for display configuration, 
I think some parameters are not handled well from the motherboard.

Chipset 845G

I have found that simply re using an old xorg.conf (uses i810) from my 
suse 9.1 days will give a reliable display and x re start on this machine.
I wish I knew more.

-- 
alan cocks
Kubuntu user#10391
Linux user #360648