Unity will not run with dual screens on Intel 940/943/945 graphics

[Colin Law]

Using up to date Quantal alpha, on a laptop with graphics chipset "Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller", which runs Unity (3d) ok, when an external display is plugged in so that the virtual desktop exceeds 2048 pixels width the chipset is no longer able to support 3d. In this situation a dialog pops up indicating that unity can not run and that unity-2d must be selected at the logon prompt. This is innapropriate as unity-2d is no longer available.
The correct behaviour would be to automatically switch to using the mechanism to be used to allow Unity to run on 2d hardware.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: unity 6.2.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-10.10-generic 3.5.1
Uname: Linux 3.5.0-10-generic i686
ApportVersion: 2.4-0ubuntu8
Architecture: i386
Date: Mon Aug 20 15:13:39 2012
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha i386 (20120730.1)
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

I think this is the maximum texture size your hardware/driver can handle. I believe the workaround for that is the enable the "Copy to texture" plugin in CCSM.

It's a very old problem. If you dig deep enough you'll find plenty of bug reports about it.

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 824099, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.

See also: bug 830949

[Colin Law (colin-law)]

That bug does not address the erroneous error message on the popup that is generated when attempting to use both displays (the error says to use unity-2d). Should I open a new bug report for that?

[Colin Law (colin-law)]

On second thoughts I will add this to bug #824099

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.