Backlight flickers between two brightness settings

Bug #442392 reported by Alex French on 2009-10-04
This bug report is a duplicate of:  Bug #415023: brightness is broken on MSI WIND U100. Edit Remove
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Ubuntu
Undecided
Unassigned

Bug Description

I'm running the Ubuntu 9.10 beta on my MSI Wind U100 (intel atom laptop with 945gme graphics). After I log in, the backlight switches between the brightest and second brightest levels at a rate of 1Hz or so. This continues until I fiddle with the backlight settings via the brightness adjustment hardware keys. After that, everything seems to work correctly. When the backlight is changing, the corresponding backlight level shows up in the OSD.

I provide extra information or test things if necessary.

ProblemType: Bug
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC1200 Analog [ALC1200 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: alex 1767 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xffe00000 irq 16'
   Mixer name : 'Realtek ALC1200'
   Components : 'HDA:10ec0888,14620110,00100101'
   Controls : 21
   Simple ctrls : 13
Date: Sun Oct 4 12:48:51 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=5a8ef317-e93e-4dbf-be5e-b3f387d473f7
MachineType: MICRO-STAR INTERNATIONAL CO., LTD U-100
Package: linux-image-2.6.31-11-generic 2.6.31-11.38
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-11-generic root=UUID=e0a87a5c-e45b-43cb-bfd4-badf84525bae ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-11.38-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-11-generic N/A
 linux-firmware 1.20
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Uname: Linux 2.6.31-11-generic i686
dmi.bios.date: 12/03/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.3
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: U-100
dmi.board.vendor: MICRO-STAR INTERNATIONAL CO., LTD
dmi.board.version: Ver.001
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: MICRO-STAR INTERNATIONAL CO., LTD
dmi.chassis.version: Ver.001
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.3:bd12/03/2008:svnMICRO-STARINTERNATIONALCO.,LTD:pnU-100:pvrVer.001:rvnMICRO-STARINTERNATIONALCO.,LTD:rnU-100:rvrVer.001:cvnMICRO-STARINTERNATIONALCO.,LTD:ct3:cvrVer.001:
dmi.product.name: U-100
dmi.product.version: Ver.001
dmi.sys.vendor: MICRO-STAR INTERNATIONAL CO., LTD

Alex French (grackle) wrote :
Alex French (grackle) wrote :

After rebooting for a kernel upgrade, the backlight flickered at the login screen and stopped flickering before I logged in.

Dmitri Petros (radjahshellduck) wrote :

Workaround. I'm on a U100 and have a similar problem both on the log in screen and after log in to desktop. I can stop the screen flickering, and make the flickering brightness widget disappear, by pressing the "right click" mouse pad bar (after the desktop is fully up) and holding it for 5-10 seconds. It is then necessary to delete the new empty folder created by the right click. Don't know why it works, but it does. Hope it works for others. :)

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