[i965] Backlight dimming not working in Hardy or Intrepid because of wrong XRandR BACKLIGHT_CONTROL setting

This bug is still present after updating packages to Hardy alpha-2

Same problem here, almost the same laptop as well: vaio sz680.

Only need the xbacklight component, so closing the -intel one.

This bug is still present in Hardy alpha 4

... and Hardy alpha 5 ...

Saw some bugs reported by debian devs, testing to see if xrandr has anything to do with this problem. Here's the output of xrandr --props on Gutsy, with xbacklight working properly.

Have found a fix

This bug can be fixed by restoring the xrandr configuration, which requires one to run the following command:

$ xrandr --output LVDS --set BACKLIGHT_CONTROL native

Which fixes the buggy config (original config attached).

This is a bug in the XRandR config so should be listed with the x driver

This bug is still present in Hardy Beta

Michael, have you found a way to get the xrandr config to stick after a reboot, I find myself having to runt he command after reboot.

Nic,

You'd need to add a script to one of the /etc/rc directories, after GDM
is started (all it would do is run that command). But really, we
shouldn't have to because the driver should configure itself.

Err, this is bug 197929 which is a kernel bug.

this works for me on VAIO SZ750

in hardy this bug is still present, in a default instalation. it is solved with the command though

This bug is still present in Intrepid Beta, where it is the only impediment to flawless hotkey control of backlight on a Sony Vaio SZ650N.

I've added Linux to the affects list because of this comment:
https://bugs.launchpad.net/linux/+bug/176888/comments/13

When you say it's a bug in the "xrandr config", what exactly do you mean?

Perhaps I misunderstand - All I really know is that I have to run that
xrandr command to get any control over my backlight, so I assume that
it's a problem with xrandr - which I'm perfectly happy to accept may be
incorrect.

Please try to use my script to gather some info about graphics card. we should find for what models change is needed, it seems not all models work with same settings.

My configuration when it does dim, after manual switch using today cd live i386, manually set to native.

with this settings, it does not do anything.

Vaio VGN FS840/W (915GM chipset) here, using the latest xserver-xorg-video-intel v2:2.4.1-1ubuntu10. I also have this problem with my backlight. After quite some time debugging the gnome brightness applet and gnome-power-manager, I realized gnome-power-manager is seemingly dependent upon xrandr. When running gnome-power-manager with --no-daemon and --verbose, I can see that it thinks the range for my brightness is (0,0). Xrandr also thinks the range is (0,0). If I change BACKLIGHT_CONTROL to legacy with xrandr, --prop will say my backlight range is (0,255), which is reflected in gnome-power-manager. Unfortunately, adjusting the BACKLIGHT with xrandr or the brightness applet does nothing (I have tried setting BACKLIGHT_CONTROL to native, kernel, legacy and combination with no results).

When I run xbacklight, it returns "nan".

If I write a value from 0 to 7 into /class/backlight/sony/brightness, my screen brightness will be adjusted. I understand this to be a function of the sony-laptop module however, not the video driver. The brightness applet doesn't use this method, so it is effectively broken.

If I use the VESA driver, xrandr and the brightness applet work as expected.

I assume this has to do with the intel video driver?

brighness don't work on sont vaio fw11e (ati card)

there sys/class/backlight/acpi_video0 instead of sony

This works on my Sony Vaio VGN-NR21E with Intel videocard,
Thanks!!

como puedo cambiar la configuracion de forma permanente

la mia funciona con este:

xrandr --output LVDS --set BACKLIGHT_CONTROL legacy

pero se cambia.... cuando inició sesión

I think this should just be an issue with xbacklight and sony laptops in general. I have an ati card and the backlight doesn't work.

Backlight control from hotkeys is now working properly in jaunty alpha 4, though more steps than the current 5 would be appreciated.

Hi,
I have a Sony sz-740. It has been 2 month I'm working on brightness but i could not solve the problem. I'm really confused. Please help me.:((. I tested everything . I'm quite disappointed! I tried "xbacklight" command but I got an error:

$ xbacklight -set 10
No outputs have backlight property

Please help me.

Mostafa:

Check the output of:
]$ lspci

What graphics card is listed? If you are running in SPEED mode it will
probably be an nVidia card and you should look here for help:
https://bugs.launchpad.net/bugs/95444

Mike

Dear Mike,

Here is the response of lspci command;

mostafa@mostafa-laptop:~$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:01.0 PCI bridge: Intel Corporation Mobile PM965/GM965/GL960 PCI Express Root Port (rev 0c)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
00:1c.2 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 3 (rev 03)
00:1c.3 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 4 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
00:1f.2 IDE interface: Intel Corporati on 82801HBM/HEM (ICH8M/ICH8M-E) SATA IDE Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 03)
01:00.0 VGA compatible controller: nVidia Corporation GeForce 8400M GS (rev a1)
06:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)
07:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8055 PCI-E Gigabit Ethernet Controller (rev 12)
09:04.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
09:04.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant IEEE 1394 Host Controller
09:04.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)
az you said it is Nvidia. What shoud I do? does brightness work in stamina mode ?

Even in STAMINA Mode I couldn't solve my problem/. I got an error executing xrandr

mostafa@mostafa-laptop:~$ xrandr --output LVDS --set BACKLIGHT_CONTROL native
X Error of failed request: 171
  Major opcode of failed request: 154 (RANDR)
  Minor opcode of failed request: 15 ()
  Serial number of failed request: 14
  Current serial number in output stream: 14

what can I do?

Mostafa:

Please attach your logs to this bug. As attachments.

/var/log/Xorg.0.log

and the output of:

]$ dmesg | cat > dmesg.log
]$ sudo lspci -vvnn | cat > lspci.log

Also, you could try booting a liveCD (or liveUSB) of Jaunty alpha4, which has improved support for backlight on Intel in Sony.

http://cdimage.ubuntu.com/releases/jaunty/alpha-4/

This was a problem for me on intrepid with a sony viao if I run " xrandr --output LVDS --set BACKLIGHT_CONTROL native" I am able to control the screen brightness with Fn-F5/6.

This bug is fixed for me after upgrading to Jaunty.
$ uname -a
Linux athena 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux

The backlight can dim correctly without having to enter a xrandr... command

Bryce, Rory

This bug is specifically targeted at Hardy and Intrepid in the title. It's nice that it's fixed in Jaunty, but it's not fixed in Hardy so shouldn't be reclassified as "Fix Released".

[This is an automatic notification.]

A new major version of the -intel driver is now available in Karmic.

This version includes a major reworking of the acceleration
architecture, which resolves a huge number of issues. We do not know
whether it resolves the issue you reported.

Would you mind testing Karmic Alpha-2 and seeing if it is still a
problem? CD ISO images are available here:

  http://cdimages.ubuntu.com/releases/karmic/

If the issue can still be reproduced on karmic, please report here with
your findings, and attach a fresh Xorg.0.log from your test, and we will
be able to forward the bug upstream.

Otherwise, if the bug no longer exists in Karmic, let us know that as
well.

In the off chance you encounter different bugs while attempting to test
Karmic, please report those as new bug reports.

This bug no longer exists in Karmic (has been fixed since Jaunty and no regressions noted).

Thanks for letting us know the issue is resolved.

i'm on karmic and
xbacklight as the gnome brightness applet don't work :(
i have an intel GMA 950 card (netbook samsung NC10)

xbacklight -get
No outputs have backlight property

Same here, on a MacBook Air, Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 03)

It is not possible to set the xrandr properties, so presumably a problem with the new xserver-xorg-video-intel driver. This bug seems relevant: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/397617

Same here, VGN-C2Z, VGA compatible controller: nVidia Corporation G72M [GeForce Go 7400] (rev a1)
Tested on Karmic, the nVidia display settings only controls contrast & brightness, NOT the brightness of the backlight.
Also area where the SONY logo is very hot, suspecting the backlight is working on full blown.

Chris
This bug is about Intel 965 graphics adapters. Yours is an nVidia, which is handled by nvclock / smartdimmer.