Comment 0 for bug 1024507

Running 12.10, updated today, on iMac 11,2 (mid 2010) with AMD Radeon 4670.
Using kernel radeon driver (lsmod shows it running).
Normal boot results in black screen. Ctl-Alt-Del reboots; indicating that system did boot.
If I place 'nomodeset' on kernel command line, main screen can be seen and unity desktop runs normally.

This appears to be a regression in the kernel, similar to bug 597070 (ubuntu 11.04 - used fglrx to get video to work) and to bug 863969 (ubuntu 11.10 - where an upgrade to the 3.2 kernel seemed to improve video detection).
Suspend and resume does not work either, not turning off the system, only the video, and resuming to a black screen.

I think the problem is in KMS, because the black screen happens even if I boot into text mode and using nomodeset fixes it. Hence filing this against xorg but expect it to go to kernel developers.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: xorg 1:7.7+1ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-4.4-generic 3.5.0-rc6
Uname: Linux 3.5.0-4-generic x86_64
.tmp.unity.support.test.1:

ApportVersion: 2.3-0ubuntu4
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Fri Jul 13 19:12:16 2012
DistUpgraded: Fresh install
DistroCodename: quantal
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes,
GraphicsCard:
 Advanced Micro Devices [AMD] nee ATI RV730 XT [Mobility Radeon HD 4670] [1002:9488] (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00b6]
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64+mac (20120509)
MachineType: Apple Inc. iMac11,2
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: vmlinuz-3.5.0-4-generic root=UUID=268e7eb7-d871-478c-a906-b719eea881ea ro nosplash nomodeset initrd=EFI\ubuntu\initrd.img-3.5.0-4-generic
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/09/11
dmi.bios.vendor: Apple Inc.
dmi.bios.version: IM112.88Z.0057.B01.1112090906
dmi.board.name: Mac-F2238AC8
dmi.board.vendor: Apple Inc.
dmi.chassis.type: 13
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F2238AC8
dmi.modalias: dmi:bvnAppleInc.:bvrIM112.88Z.0057.B01.1112090906:bd12/09/11:svnAppleInc.:pniMac11,2:pvr1.0:rvnAppleInc.:rnMac-F2238AC8:rvr:cvnAppleInc.:ct13:cvrMac-F2238AC8:
dmi.product.name: iMac11,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.8+bzr3249-0ubuntu2
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.33-3
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.3-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.3-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.12.1.902-1ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.19.0-1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.1-1build1