cannot change screen brightness on Sony VAIO VGN-FS285M

[Luis Alberto Pabón]

Binary package hint: kde-guidance

The KDE applet for guidance-power-manager seems to ignore screen brightness settings, ie, I drag the screen brightness slider to the lowest setting for "mains powered" and apply, but screen brightness doesn't change (even if I unplug&plug power to force it).

That said, screen brightness adjustment in power profiles work when they are configured in powersaved config files (such as /etc/powersave/scheme_powersave). It just seems that the kde applet cannot change the screen brightness at all, but powersaved can.

This is a Sony VAIO VGN-FS285M (centrino), on Kubuntu Feisty (updated as of today).

PS: this very same behaviour existed in Edgy.

[Luka Renko (lure)]

I suspect that HAL does not have proper support for your laptop brightness settings.

Can you run guidance-power-manager from command line (terminal/console) and reproduce the problem and then provide output of the command?

[Luis Alberto Pabón (copong)]

Hi Luka. I've run the applet from the command line (/usr/share/python-support/kde-guidance/guidance-power-manager.py) but it doesn't produce any output to the console no matter what I do on the gui (change screen brightness, cpu speed, the works). The only output I get after plugging/unplugging:

Warning: While setting SystemPowerManagement to True : org.freedesktop.Hal.Device.SystemPowerManagement.NotSupported: No powersave method found
Warning: While setting SystemPowerManagement to False : org.freedesktop.Hal.Device.SystemPowerManagement.NotSupported: No powersave method found

Am I doing something wrong?

[Luka Renko (lure)]

No, it just means that HAL call to change brightness succeeded (no error by powermanager), but it silently failed (did not change brightness). So this is more likely HAL or kernel issue.

Changing module to hal.

[Luis Alberto Pabón (copong)]

Thanks, Luka :)

By no means I'm an expert, but I am unsure about it being a kernel problem,
after all the powersave daemon does change my screen brightness when I plug
and unplug (I know is not guidance because works just the same on a console
session with no X loaded).

Is there any debug information I can produce to help clarify the issue? I
have looked around but couldn't find a hal log file under /var/log or
anything, and syslog/daemonlog don't tell me anything either.

On 04/05/07, Luka Renko <email address hidden> wrote:
>
> No, it just means that HAL call to change brightness succeeded (no error
> by powermanager), but it silently failed (did not change brightness). So
> this is more likely HAL or kernel issue.
>
> Changing module to hal.
>
> ** Changed in: hal (Ubuntu)
> Sourcepackagename: kde-guidance => hal
>
> ** Summary changed:
>
> - guidance-power-manager doesn't change screen brightness
> + cannot change screen brightness on Sony VAIO VGN-FS285M
>
> --
> cannot change screen brightness on Sony VAIO VGN-FS285M
> https://bugs.launchpad.net/bugs/102294
> You received this bug notification because you are a direct subscriber
> of the bug.
>

--
Luis Pabón

[Luka Renko (lure)]

Good to know powersave daemon works. Then it is probably missing/buggy implementation in HAL. powersave daemon uses own methods to control PM/brightness, therefore it can work, while HAL/Guidance-Power-Manager/GNOME-Power-Manager do not as they depend on proper implementation in HAL.

You may want to search in HAL mailing lists if this was already addressed recently (0.5.9 was just released, while feisty uses 0.5.8). I do not know about log files...

[Luis Alberto Pabón (copong)]

I followed your suggestion and found this:
http://lists.freedesktop.org/archives/hal/2007-January/006966.html

I'll try to build the ubuntu hal package with that patch to see what happens...

[Luis Alberto Pabón (copong)]

It turned out that Ubuntu's HAL has that patch already.

I found this one too:
http://lists.freedesktop.org/archives/hal/2007-February/007203.html

Which I applied to HAL to no avail :(

[Peter (sunspots-deactivatedaccount)]

I'm unable to adjust the brightness using the function keys on the laptop.

I will try running guidance-power-manager to see if I can adjust from there.

Further, the brightness doesn't change when I unplug the power source.

System:
- Fujitsu Lifebook S6410P laptop
- Intel Centrino Core 2 Duo T7500 (64-bit)
- RAM: 2Gig
- kubuntu Gutsy Gibbon Tribe-5

[Luis Alberto Pabón (copong)]

Seems fixed in gutsy.

[Peter (sunspots-deactivatedaccount)]

Still a problem for me on Fujitsu.

Gutsy Tribe-5 with latest updates (16 Sept 2007)

[Launchpad Janitor (janitor)]

[Expired for hal (Ubuntu) because there has been no activity for 60 days.]

[Peter (sunspots-deactivatedaccount)]

Trying to reactivate this bug report since Launchpad Janitor indicated no activity for 60 days. However, the issue still remains and made comment on such only 5 days prior to Janitor.

[Peter (sunspots-deactivatedaccount)]

Still a problem on Fujitsu Lifebook S6410P.

Installed Kubuntu 8.10 Intrepid Ibex with all updates as of 16th Nov 2008.

Also, the brightness does not change when power unplugged.