[HP Pavillion dm3-1109TU] Brightness setting not remembered after reboot

[chris]

With Ubuntu 14.04.1 with system updated today, I found that screen brightness not remembered after reboot. Always back to 100% in every system startup.

In Ubuntu 12.04 (kernel 3.2.0-67.101) brightness always reset to 0% after reboot.

I can't do testing with kernel 3.16 rc7 because of the problem I told in Bug #1349080 :
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349080/comments/5

Laptop :
HP Pavillion dm3
Product: WJ845PA#UUF
Model: dm3-1109TU

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-32-generic 3.13.0-32.57
ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic i686
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: christian 1304 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Jul 29 02:20:22 2014
InstallationDate: Installed on 2014-07-28 (0 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release i386 (20140722.2)
MachineType: Hewlett-Packard HP Pavilion dm3 Notebook PC
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic root=UUID=4a7a7692-e75c-4e75-a27f-978a30e8bff1 ro plymouth:debug splash quiet drm.debug=0xe
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-32-generic N/A
 linux-backports-modules-3.13.0-32-generic N/A
 linux-firmware 1.127.5
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/16/2010
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: F.19
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 3649
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 41.3D
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnInsydeCorp.:bvrF.19:bd11/16/2010:svnHewlett-Packard:pnHPPaviliondm3NotebookPC:pvr0487110000241F10110120000:rvnHewlett-Packard:rn3649:rvr41.3D:cvnHewlett-Packard:ct10:cvrN/A:
dmi.product.name: HP Pavilion dm3 Notebook PC
dmi.product.version: 0487110000241F10110120000
dmi.sys.vendor: Hewlett-Packard

[Brad Figg (brad-figg)]

This change was made by a bot.

[chris (ign-christian)]

Same result using latest Ubuntu 12.04 with kernel 3.13.0-32-generic

[chris (ign-christian)]

Looks like it never works.. *sigh*

I usually using 0% brightness so I didn't realize that since kernel 3.2 in Precise, brightness always reset to 0% after reboot.

After did testing with several kernels, following it's the results:
- from kernel 3.2 (since Ubuntu 12.04.2) until 3.11.0-14.21 -> brightness always reset to 0% after reboot
- from kernel 3.11.0-15.22 until 3.13.0-32.57 -> brightness always reset to 100% after reboot