Garbled screen _sometimes_

[Vassilis Pandis]

I have a whitebox laptop. Sometimes:

1. When changing from vt7 to vt1{2,3,4} and back to vt7

2. When the screensaver fade-out begins and I move the mouse before it completes

3. When the screensaver is running and I move the mouse

I get a garbled picture. I can't take a photo of it, but nothing can be read, I get black where it should be white and distorted fonts. ctrl+alt+f1 followed by ctrl+alt+f7 fixes it _always_. It doesn't happen always, just sometimes (I have this laptop for a month now and I can't figure out if there is a way to reliable reproduce this). It never happens when the computer boots (i.e. the first gdm login screen is always ok).

I was hesitant to report this because it's not a showstopper _IF_ you know how to switch virtual terminals. Otherwise, it renders the machine completely useless. If you need any information, please let me know.

( I'm really sorry that is an obscure bug )

[Vassilis Pandis (pandisv)]

This is with current Edgy.

[Vassilis Pandis (pandisv)]

This happens without XGL as well as with compiz set up. It doesn't happen with the nvidia driver (I have other minor problems with that :-)

[Francis Bond (bond)]

G'day,

I can confirm that I also get this bug, and that switching to a console and back undoes the garbling (thanks for the tip).

The graphics card is an nVidia Quadro NVS 285
$ lspci -vv | grep -i nvidia
7:00.0 VGA compatible controller: nVidia Corporation NV44 [Quadro NVS 285] (rev a1) (prog-if 00 [VGA])
        Subsystem: nVidia Corporation Unknown device 0334

The system is a Dell precision 490, running ubuntu edgy amd64.

I would be happy to provide more information if it would help,

Francis Bond <email address hidden>

[Timo Aaltonen (tjaalton)]

Please test Feisty beta if it is fixed there.

[Bryce Harrington (bryce)]

I have a Dell precision 380 with this Quadro NVS 285 card and a VX2025wm monitor. I've installed Feisty on it, and have not seen this behavior.

Can anyone confirm whether the problem still occurs on Feisty? If not, I think we can close this as fixed.

[Kari Aliranta (kpaliran)]

Still there in Feisty, probably - I'm not exactly sure if it's the same bug. I'm using the nv driver, and the picture gets garbled: colours don't change, but the horizontal width of the picture always lessens, ungracefully, so that you have a chaotic mix of colours and shapes on your screen, though you can sometimes make something out of it. A visit in a virtual terminal corrects the situation, as does switching the resolution back and forth - changing a media player etc. to full screen and back doesn't have any effect, however. Sidenote: there are no compositing windows managers in use in my computer.

This problem only shows up occasionally, and only when starting a new video with Gxine or VLC.

I also tried taking a screenshot of my garbled screen, but when viewed, it was completely normal.

[Timo Aaltonen (tjaalton)]

Try adding 'Option "HWCursor" "false"' in the Device section. Could help..

[Timo Aaltonen (tjaalton)]

No reply from the reporter, closing the bug.