Bug#443111: laptop: can't set brightness from within X11
Dirk Griesbach wrote:
> On Tue, Sep 18, 2007 at 09:44:56PM +0200, Brice Goglin wrote:
>
>> You should probably use the xbacklight tool (xbacklight package) instead
>> of the brightness control keys. The latter might change things in the
>> back of the driver (through the BIOS), causing possible problems.
>>
>
> I think xbacklight is more like a work around but not a real solution.
> The brightness settings with acpi buttons do work right now with the old
> driver and I can't get the point why the newer driver refuses to use the
> functionality. brightness control keys don't change things without
> noticing the operating system. Every change to the brightness is noticed
> in /sys/class/backlight/acpi_video0/actual_brightness.
>
No, xbacklight is not considered as a workaround. Given that ACPI is
often considered as a huge mess trying to specify the whole world and
that half of these specs are bad while the other half is not respected
by most vendors, not using ACPI is actually sometimes a good idea.
xbacklight uses the RandR protocol to change the brightness when the
xorg driver implements it (using direct writes to the board registers,
no using ACPI at all). I would personally trust the X.org drivers much
more than ACPI...
Anyway, did you try xbacklight with driver 2.1.1?
> No. These drivers did lock my system too often if switching between VT
> and X11 or exiting Xfce back to xdm so I didn't used them much. The
> newest driver does freeze less often. But next weekend I will have a bit
> more time to play. :-) Just now I switched back to the old driver.
> Brightness keys work like a charm, no freeze if switching from X11 to VT
> or if exiting Xfce and reentering xdm... Good old times ;-)
>
But no RandR 1.2 either. It all depends on what's important for you :)
Brice
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