8086:0166 [Asus Taichi31] 2nd Backside Screen Backlight

[Axel Huebl]

The backlight on my Taichi31´s 2nd screen (that is the touchscreen on the backside working like a tablet) is nearly black (but as far as I can test working).

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-15-generic 3.11.0-15.23
ProcVersionSignature: Ubuntu 3.11.0-15.23-generic 3.11.10
Uname: Linux 3.11.0-15-generic x86_64
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: steffi 2028 F.... pulseaudio
Date: Fri Jan 10 00:59:35 2014
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=56c8dabe-0ddc-4b93-bc89-732bbe4fe654
MachineType: ASUSTeK COMPUTER INC. TAICHI31
MarkForUpload: True
ProcEnviron:
 LANGUAGE=de_DE
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.11.0-15-generic root=UUID=0e7230c6-d126-4b9e-adf3-2cd0add113cd ro quiet splash vt.handoff=7
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-15-generic N/A
 linux-backports-modules-3.11.0-15-generic N/A
 linux-firmware 1.116
SourcePackage: linux
UpgradeStatus: Upgraded to saucy on 2014-01-09 (0 days ago)
dmi.bios.date: 01/31/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: TAICHI31.207
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: TAICHI31
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrTAICHI31.207:bd01/31/2013:svnASUSTeKCOMPUTERINC.:pnTAICHI31:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnTAICHI31:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.name: TAICHI31
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.

[penalvch (penalvch)]

Axel Hübl, thank you for reporting this and helping make Ubuntu better. Could you please confirm this issue exists with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ . If the issue remains, please just make a comment to this.

If reproducible, could you also please test the latest upstream kernel available (not the daily folder) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.13-rc7

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

[Axel Huebl (axel-huebl)]

I tested the trusty daily snapshot with `linux-headers-3.13.0-1` which should be the kernel mainline
  v3.13-rc7-trusty
you mentioned in the second section.

So: also not fixed in kernel upstream.

[penalvch (penalvch)]

Axel Hübl, thank you for performing the requested test. The issue you are reporting is an upstream one. Could you please report this problem through the appropriate channel by following the instructions _verbatim_ at https://wiki.ubuntu.com/Bugs/Upstream/kernel ?

Please provide a direct URL to your e-mail to the mailing list once you have made it so that it may be tracked.

Thank you for your understanding.

[Axel Huebl (axel-huebl)]

Thank you I will try to do that.

Actually, the instructions in the link you posted are quite crappy: it starts with "please follow this format" ... long list ... but I do not even know for _what_...

An E-Mail? A Launchpad bug? A html formular?
Shall I write that information in a text file?

... This guide could need some refactoring for noobs like me :)

[Axel Huebl (axel-huebl)]

Could you give me a hint which maintainer takes care of that?
So I do not have to send it to <email address hidden> ... Thanks!

[penalvch (penalvch)]

Axel Hübl, given this would appear to be a backlight problem, in that it is not showing up well, you may want to start with linux-acpi.

[Axel Huebl (axel-huebl)]

Posted:
  http://marc.info/?l=linux-acpi&m=138934278107520&w=2

[penalvch (penalvch)]

Axel Hübl, thank you for your comment. Unfortunately, your upstream post has a sever problem with it, in that you tested with the downstream kernel, not the upstream kernel as outlined in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1267646/comments/4 . Your post would most likely either be ignored, or if by a miracle, upstream will ask you to test the upstream kernel, which testing the downstream kernel is not doing. It doesn't matter how well synced with the upstream kernel the Ubuntu kernel is, if it doesn't look like the upstream kernel it doesn't fly.

[Axel Huebl (axel-huebl)]

As I told you, the link does not help so much finding that version of the kernel.
Which one shall I use from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D ?
 linux-3.11.y.z-review
?

Because all the kernels listed there are ubuntu flavored...

[Axel Huebl (axel-huebl)]

Example: if I follow the instructions I shall use the daily folder:
  http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2014-01-09-trusty/

but even this one contains ubuntu specific configs if I am right?
( 0003-configs-based-on-Ubuntu-3.13.0-1.16.patch )

[penalvch (penalvch)]

Axel Hübl -> http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc7-trusty/

[Axel Huebl (axel-huebl)]

All right, I will go for that in the evening.
Is it ok to test that kernel on saucy or is it required to use trusty for that?

[penalvch (penalvch)]

Axel Hübl, testing it in Saucy is fine.

[Axel Huebl (axel-huebl)]

Christopher M. Penalver,

I installed and booted into the Kernel at http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc7-trusty/ and it still looks flavored:

> cat /proc/version
> Linux version 3.13.0-031300rc7-generic (apw@gomeisa) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #201301041835 SMP Sat Jan 4 23:36:50 UTC 2014

Are you sure that is the right version? Looks still like an Ubuntu flavor to me.

Installed packages:
> dpkg -i linux-*-3.13.0-031300rc7-generic_3.13.0-031300rc7.201301041835_amd64.deb

[penalvch (penalvch)]

Axel Hübl, as per the Ubuntu Kernel Team -> https://wiki.ubuntu.com/Kernel/MainlineBuilds this is a fully unmodified, upstream kernel, packaged into a .deb for convenient testing.

Despite this, you may want to resubmit as previously advised, but you may find they already dismissed it as downstream noise.

[Axel Huebl (axel-huebl)]

I can do that. I am just wondering how it shall *not be considered* downstream noise if even the /proc/version says "hey I am ubuntu".

I mean, there is even a
  0003-configs-based-on-Ubuntu-END.patch
in there.

IMHO it looks as there was no clean mainline .deb in this link newer then 2.x ...

[Axel Huebl (axel-huebl)]

Fingers crossed:
  http://marc.info/?l=linux-acpi&m=138938058419187&w=2

[Axel Huebl (axel-huebl)]

Discussion migrated to:
  https://bugzilla.kernel.org/show_bug.cgi?id=68631