Ubuntu 9.04, Intel display driver problem (looks like bug 375545 is still with us)

[Chris G]

On Mon, Jul 06, 2009 at 08:25:06PM +0100, Chris G wrote:
> I have just upgraded from xubuntu 8.10 to xubunto 9.04 and am having
> big problems with Xorg.  What happens is that the Xorg Intel drivers
> fail to detect any display, drop into failsafe mode and exit.
> 
> Fortunately, for some reason, Xorg also attempts to start up with vesa
> drivers and they work OK and produce a working display on console
> number 9 (the Intel drivers having used console 7).
> 
> When I boot the system I see a series of messages from the failing
> Intel drivers saying the system is failing back into "Low Graphics
> Mode" then a message from the Vesa driver saying that display :0 is in
> use so that it will start up on display :1 instead.
> 
> It looks to me as if this is bug 375545 as the messages I see in
> Xorg.0.log are just the same as reported in that bug report.  However
> bug 375545 is shown as fixed by xserver-xorg-video-intel version
> 2:2.7.1 but I have installed these drivers and still have the fault.
> 
> I have posted a message to bug 375545 on Launchpad but how do I
> escalate things so it gets back to being a live bug.  I'm quite
> prepared to believe I have done something silly but, if I have, I need
> some help to find out what it is.
> 
Hmmm!  I've fixed the problem, I *suspect* it was a faulty DVI-D cable
which meant that the Intel video drivers didn't recognise the display
for some reason.  While Googling the problem I saw someone else had a
similar problem with a faulty lead so I thought I'd try it.

The sequence I went through was:-

    Shut system down.

    Switch to analogue VGA (same monitor, same on-board graphics, just
    a change of lead) and the problem went away although the quality
    at 1600x1200 was rather poor.

    Shut system down.

    Fully turned off monitor (removed power supply connector).

    Removed analoge VGA connector, connected up a new/different DVI-D
    connector, powered up and everything worked perfectly.  Only one X
    process, correct Intel drivers running.  :-)

Lesson learnt, don't always assume it's a software problem and don't
always assume that nothing else has happened to the system while doing
an upgrade.  Presumably I (or the dog) had done something to that
faulty DVI-D lead around the same time as I upgraded from 8.10 to 9.04.

-- 
Chris Green