As the summary says. This is 100% repeatable and there's been a fair amount of traffic about it on various lists.
The current concensus is that the root cause is down to to powersave mode tweaks in all GPU modules
To repeat:
install multiple nvidia GPUs in a desktop system (or a multi-gpu card such as nvidia Quadro CVS440)
Boot up Trusty beta versions (or 2.13 kernel).
try configuring displays using standard tools based on xrandr
This worked fine in Saucy (crosscheck: boot off 13.10 64bit DVD)
Apparently this is fixed in the 2.14 kernels.
It can be worked around by manually configuring the devices in xorg.conf and enabling Xinerama, BUT - this results in massive slowdown and as this disables xrandr a number of important apps (such as vlc) will refuse to run.
This is a major regression and needs to be treated as such.
---
ApportVersion: 2.14.1-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: alan 3033 F.... pulseaudio
/dev/snd/controlC0: alan 3033 F.... pulseaudio
DistroRelease: Ubuntu 14.04
HibernationDevice: RESUME=UUID=68be2b9c-e944-4f7e-996d-7360074299d3
IwConfig:
irda0 no wireless extensions.
eth0 no wireless extensions.
lo no wireless extensions.
NonfreeKernelModules: zfs zunicode zavl zcommon znvpair spl
Package: linux (not installed)
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-23-generic ro boot=zfs root=ZFS=MAGENTA/ROOT/RARING-1 rpool=MAGENTA elevator=noop panic=30 reboot=w zswap.enabled=1 bootdegraded=true nomdmonddf nomdmonisw
ProcVersionSignature: Ubuntu 3.13.0-23.45-generic 3.13.8
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-3.13.0-23-generic N/A
linux-backports-modules-3.13.0-23-generic N/A
linux-firmware 1.127
RfKill:
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
Tags: petra
Uname: Linux 3.13.0-23-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:
_MarkForUpload: True
dmi.bios.date: 08/07/2008
dmi.bios.vendor: Intel Corp.
dmi.bios.version: JOQ3510J.86A.0942.2008.0807.1958
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: DQ35JO
dmi.board.vendor: Intel Corporation
dmi.board.version: AAD82085-803
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrJOQ3510J.86A.0942.2008.0807.1958:bd08/07/2008:svntranstecAG:pn:pvr:rvnIntelCorporation:rnDQ35JO:rvrAAD82085-803:cvn:ct3:cvr:
dmi.sys.vendor: transtec AG
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1303150
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.