[i945] Windows and desktops flicker and flash black with Compiz enabled with the Intel video driver (945GM)

[Bálint Magyar]

Binary package hint: xserver-xorg-video-intel

Ubuntu Hardy Beta + all updates as of the date of posting on a Clevo notebook with an Intel GMA-950 graphics controller (945GM motherboard chipset).

I've found that the black flashes and flickers appear in two cases reliably:
1) When initializing the "Expose" plug-in, all virtual desktops flash black in their entirety.
2) When switching virtual desktops with the "Desktop Wall" plug-in, during the animation and on the destination desktop, windows and the desktop flash.

Knowing that EXA has been enabled by default for the Intel driver recently, I've tried AccelMethod XAA, but the flashes are still there. Also played with combinations of FramebufferCompression, TripleBuffer and PageFlip to no avail.

[Bálint Magyar (balintm)]

A bit of correction that might be important: when switching desktops, only the FOCUSED window flashes black, and then the desktop, both once. With Expose activated, desktops and windows flash randomly, BUT not windows that have been resized with the Shelf plug-in. Odd.

[Bálint Magyar (balintm)]

Something else I've discovered. Unticking "Detect refresh rate" and changing the "Refresh rate" option in compizconfig-settings-manager, I can reduce the flickers to zero once I reach 23. (default being 60) 24 gave me a single flicker in a LOT of Expose activations, 25 a bit more, up to 200 where the flickers combine into a huge black tear around the middle diagonally.

[Bryce Harrington (bryce)]

Interesting; can you reproduce the issue with compiz disabled, or only with compiz?

Also, please attach your Xorg.0.log - we may need your PCI ID if it ends up being something particular to your hardware.

[Bálint Magyar (balintm)]

Couldn't reproduce with Metacity, all fine and dandy there.

[Bálint Magyar (balintm)]

Odd, I have FramebufferCompression disabled in xorg.conf, yet there are messages about fbc being disabled in the logs.

[Bryce Harrington (bryce)]

Given that it works ok in metacity, and all the X options tested made no difference, and that the Expose plugin seems to have a role here, this probably needs to be looked at by a compiz person first, so reassigning package.

[Bálint Magyar (balintm)]

I can reproduce the problem 100% of time if I open a site that has some client-side dynamic content, in for example http://www.engadget.com/ 's case, there's the rolling news box with big images on the top right. If I have that on-screen in Opera or Firefox and initiate Expose, the screen flickers everytime the box animates. Happens with embedded Flash also, although less prominently than with rapid updates caused by JavaScript animations.

I'm not sure what triggers the flashes when I'm switching desktops on the Desktop Wall, but it happens ~75% of the time.

Thank you for your time, Bryce!

[Bálint Magyar (balintm)]

Reinstalled Hardy from scratch, cannot reproduce. No sign of flickering whatsoever.

[Randall Leeds (randall-leeds)]

Could you please post your working X11 file? Thanks.

[Robert Ancell (robert-ancell)]

Thanks for your bug report. The symptoms provided indicate this is a problem with your video drivers and is being reassigned to the xorg package. For more information on problems with visual effects and video drivers see http://wiki.ubuntu.com/VisualEffects.

[Bryce Harrington (bryce)]

[This is an automatic notification.]

A new major version of the -intel driver is now available in Karmic.

This version includes a major reworking of the acceleration
architecture, which resolves a huge number of issues. We do not know
whether it resolves the issue you reported.

Would you mind testing Karmic Alpha-2 and seeing if it is still a
problem? CD ISO images are available here:

  http://cdimages.ubuntu.com/releases/karmic/

If the issue can still be reproduced on karmic, please report here with
your findings, and attach a fresh Xorg.0.log from your test, and we will
be able to forward the bug upstream.

Otherwise, if the bug no longer exists in Karmic, let us know that as
well.

In the off chance you encounter different bugs while attempting to test
Karmic, please report those as new bug reports.

[gilrim (jsl-elvenhome)]

I'm experiencing the same issues on 9.10 a3, just installed and updated. All accelerated rendering results in flickering and windows jumping :|

[gilrim (jsl-elvenhome)]

just noticed you where requesting Xorg.0.log, here's a copy of my current

[Geir Ove Myhr (gomyhr)]

gilrim, it seems that this bug has been fixed for the original reporter. Could you file a new bug for your problem (referencing this if you would like)? You may use this bug for looking up what information should be attached to the bug (actually: file the bug with the command `ubuntu-bug -p xserver-xorg-video-intel`, that will upload a lot of relevant information). Look at the questions asked in the comments to this bug report and include that information in your bug report.

PS: Launchpad is encouraging you strongly to look for other similar bug reports when filing bugs. For xorg-related bugs, this is actually unfortunate, since different bugs may lead to the exact same behaviour. So just go ahead and file a new bug report despite what launchpad is telling you.