Unable to adjust backlight brightness after upgrade to raring - Asus UX32VD

[2xyo]

Hi,

After upgrading to raring, gsd-backlight-helper seems to make a wrong decision on which backlight to modify/the correct node is missing. The hotkeys for changing the screen brightness don't work on Asus UX32VD. The brightness is stuck between two values ​​ with the hotkeys (about 95% and 90%)

gsd-backlight-helper sets /sys/devices/virtual/backlight/apple_backlight/brightness which doesn't change anything :

# strace -e write,open /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness 10 2>&1|tail -n 2
open("/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0/brightness", O_WRONLY) = 3
write(3, "10", 2) = 2

manually setting the brightness like this doesn't work :

# echo 5 > /sys/devices/pci0000\:00/0000\:00\:01.0/0000\:01\:00.0/backlight/acpi_video0/brightness

setting the brightness using intel_backlight works well :

# strace -e write,open /usr/bin/intel_backlight 100 2>&1|tail -n 4
open("/sys/bus/pci/devices/0000:00:02.0/resource0", O_RDWR|O_CLOEXEC) = 4
write(1, "current backlight value: 100%\nse"..., 52current backlight value: 100%
set backlight to 100%
) = 52

manually setting the brightness like this works :

# echo 50 > /sys/bus/pci/devices/0000\:00\:02.0/backlight/acpi_video1/brightness

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: gnome-settings-daemon 3.6.4-0ubuntu8
ProcVersionSignature: Ubuntu 3.8.0-16.26-generic 3.8.5
Uname: Linux 3.8.0-16-generic x86_64
ApportVersion: 2.9.2-0ubuntu5
Architecture: amd64
Date: Sun Apr 7 07:41:38 2013
InstallationDate: Installed on 2012-09-17 (201 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64+mac (20120917)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-settings-daemon
UpgradeStatus: Upgraded to raring on 2013-04-06 (0 days ago)

[2xyo (2xyo)]

An upgrade to the last firmware solves the bug ( BIOS 214 2013/03/07)

This report can be closed.

[Nicolas Joyard (joyard-nicolas)]

I confirm the bug is solved with BIOS 214.

[Florian Hars (hars)]

The same thing happens on an Thinkpad X230 after an update to 13.04

[wb8nbs (wb8nbs)]

I have an Asus N56VJ that exhibited the same behavior on 12.10. I installed kernel 3.7.0-7 from Xorg-edgers and the F5-F6 backlight keys now work correctly. I consider the backlight adjustment to be critical as in a dimly lit room, the screen is so bright it hurts your eyes.

I tried a 13.04 live distro from one of the magazine DVDs. Activating the backlight keys showed the previous incorrect behaviour as described in this bug.

The Bios on this N56VJ is verion 203 and that is the only one shown on the Asus web site. I asked Asus support if there was a 214 update for this model and they said no.

So I will not be doing 13.04.

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/GNOME. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.

[oliver (oliver-schinagl)]

Been using 14.04 for a few days, maybe 2 weeks now, and initially it worked fine.

After suspending for a day today however (no updates installed) gsd-backlight-helper now targets acpi_video0 instead of intel_backlight which results in not functinoal backlight. /usr/bin/intel_backlight works as before, but I'd expect that gsd-backlight-helper would use some smarts to pick a backlight or atleast allow it to be configurable?

Long story short, gsd-backlight-helper seems to not consistently pick the correct backlight.
Or
acpi_video0 isn't linked to intel_backlight?

This on a macbook pro 13 retina (11,1)