Since the upgrade to kernel 3.13.0-35 (from 3.13.0-34), the screen is very dark to the point it's unusable.
Backlight seems completely turned off. Using the brightness keys doesn't help.
It was working fine with 3.13.0-34.
I found that the offending patch is "drm/radeon: set default bl level to something reasonable".
I reverted this patch and recompiled 3.13.0-35, and it solved the problem.
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ApportVersion: 2.14.1-0ubuntu3.3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC2: greg 1962 F.... pulseaudio
/dev/snd/pcmC2D0p: greg 1962 F...m pulseaudio
/dev/snd/controlC1: greg 1962 F.... pulseaudio
/dev/snd/controlC0: greg 1962 F.... pulseaudio
CurrentDesktop: KDE
DistroRelease: Ubuntu 14.04
HibernationDevice: RESUME=UUID=fa1d286a-7f50-4e1f-ae6c-9d48161e6c2d
InstallationDate: Installed on 2010-07-03 (1521 days ago)
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427)
MachineType: FUJITSU SIEMENS AMILO Xi 2550
Package: linux (not installed)
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-35-generic root=UUID=7b8ed785-f136-4231-b6bd-5e175a9aef0b ro processor.max_cstate=1 radeon.dpm=1 quiet splash crashkernel=384M-:128M vt.handoff=7
ProcVersionSignature: Ubuntu 3.13.0-35.62-generic 3.13.11.6
RelatedPackageVersions:
linux-restricted-modules-3.13.0-35-generic N/A
linux-backports-modules-3.13.0-35-generic N/A
linux-firmware 1.127.5
Tags: trusty
Uname: Linux 3.13.0-35-generic x86_64
UpgradeStatus: Upgraded to trusty on 2014-05-08 (116 days ago)
UserGroups: adm admin bluetooth cdrom dialout lpadmin plugdev sambashare vboxusers wireshark
_MarkForUpload: True
dmi.bios.date: 09/30/2008
dmi.bios.vendor: Phoenix
dmi.bios.version: 1.15
dmi.board.name: F44
dmi.board.vendor: FUJITSU SIEMENS
dmi.board.version: 00030D005503B103
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU SIEMENS
dmi.modalias: dmi:bvnPhoenix:bvr1.15:bd09/30/2008:svnFUJITSUSIEMENS:pnAMILOXi2550:pvr:rvnFUJITSUSIEMENS:rnF44:rvr00030D005503B103:cvnFUJITSUSIEMENS:ct10:cvr:
dmi.product.name: AMILO Xi 2550
dmi.sys.vendor: FUJITSU SIEMENS
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1364148
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.