No display backlight during plymouth bootscreen

[Jonas Schwabe]

I installed 12.10 with full disc encryption and therefore need to put my password in every time I boot my laptop.
The input field is only visible on every second boot (when the Grub menu was visible beforehand). I did some further testing and found out that I the password is accepted even if the field is not visible.
When I booted last time I saw a very dark image on the screen, with disabled back light. Enabling the back light (Fn + F5 on my system) works without problems.
Short time before the login screen becomes visible the display gets bright and few seconds of Plymouth (mouspointer is already visible etc.) are shown.

What I expected:
Plymouth takes care about enabling the back light.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: plymouth 0.8.4-0ubuntu3
ProcVersionSignature: Ubuntu 3.5.0-15.22-generic 3.5.4
Uname: Linux 3.5.0-15-generic x86_64
ApportVersion: 2.5.2-0ubuntu4
Architecture: amd64
Date: Sun Sep 23 17:54:45 2012
DefaultPlymouth: /lib/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Beta amd64+mac (20120922)
MachineType: Dell Inc. Vostro 3350
ProcCmdLine: BOOT_IMAGE=/vmlinuz-3.5.0-15-generic root=/dev/mapper/ubuntu-root ro quiet splash vt.handoff=7
ProcFB:
 0 inteldrmfb
 1 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.5.0-15-generic root=/dev/mapper/ubuntu-root ro quiet splash vt.handoff=7
SourcePackage: plymouth
TextPlymouth: /lib/plymouth/themes/ubuntu-text/ubuntu-text.plymouth
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/30/2011
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A07
dmi.board.name: 0M516T
dmi.board.vendor: Dell Inc.
dmi.board.version: A07
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: Not Specified
dmi.modalias: dmi:bvnDellInc.:bvrA07:bd09/30/2011:svnDellInc.:pnVostro3350:pvrNotSpecified:rvnDellInc.:rn0M516T:rvrA07:cvnDellInc.:ct8:cvrNotSpecified:
dmi.product.name: Vostro 3350
dmi.product.version: Not Specified
dmi.sys.vendor: Dell Inc.

[Steve Langasek (vorlon)]

Plymouth should not be touching the backlight at all - the kernel should be handling this by default at boot. Reassigning.

[Jonas Schwabe (jonas-schwabe)]

Same problem with shut down animation.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.6 kernel[0] (Not a kernel in the daily directory) and install both the linux-image and linux-image-extra .deb packages.

Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. Please only remove that one tag and leave the other tags. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text.

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.6-rc7-quantal/

[Jonas Schwabe (jonas-schwabe)]

After the last kernel update this seems to be fixed. I will have a look at it over the next days. If it does not reappear I will not test against mainline kernel.

[Joseph Salisbury (jsalisbury)]

Thanks for the update. Also, please mark this bug as "Fix Released" if you confirm it is in fact fixed.