sony-vaio-z-series team mailing list archive

[Joël Bourquard <joel.bourquard@xxxxxxxxx>]

Hi Michael,

Thanks for the hint. Indeed I was booting with "acpi_backlight=vendor".  I
removed it and now I get brightness levels 0-8 in KDE (instead of the 0-4)
which matches userspace. It's still quite bad, but it's an improvement
already.

Now, I'm always running in Stamina mode - so I'll try to add the
intel_backlight module and see what happens...

Since removing the acpi_backlight parameter changed the KDE behavior, maybe
I should try to re-introduce the parameter, but with a different value in
order to (hopefully) force it to use the Intel backlight values?  Or is it
impossible to do?

Best regards,

Joël



On Tue, Feb 14, 2012 at 6:21 PM, Michael Zugelder <michael@xxxxxxxxxxxx>wrote:

> On Di, 2012-02-14 at 17:22 +0100, Joël Bourquard wrote:
> > Today I just compiled the latest Linux kernel 3.2.6 on my Z13.  Once I
> boot
> > into KDE, I have 20 usable brightness levels (let's say 0-19).
>
> Hi,
>
> I'm also running 3.2.6 (with sony-laptop v0.9np8) and KDE (4.8) on a
> Z11. The brightness keys map to 10 levels, while the slider from the
> battery monitor applet seems to have 100+ levels.
>
> I looked around in the filesystem and found the switches:
>  /sys/devices/pci.../drm/card0/card0-eDP-1/intel_backlight/
>  /sys/devices/pci.../backlight/acpi_video0/
>
> It seems intel_backlight/ is used on my machine, which has a
> max_brightness of 4882. It works great and allows extremely fine control
> from completely off to max brightness.
>
> On the other hand, acpi_video0/ has a max_brightness of 8 and the
> brightness switching doesn't work at all.
>
> > Does someone know a way to fix this? I looked at the "sony-laptop.c"
> source
> > code and the #define SONY_MAX_BRIGHTNESS is equal to 8 in both files...
>
> I'm currently running without any additional commandline parameters, are
> you running with acpi_backlight=vendor?
>
>
> Michael
>
>