Brightness control in FreeBSD 10.1-RELEASE

Polytropon freebsd at
Thu May 21 12:01:26 UTC 2015

On Thu, 21 May 2015 17:17:45 +0530, Avinash Sonawane wrote:
> Another observation:
> I can change the brightness (increase/decrease) while FreeBSD is
> booting so it looks like FreeBSD does properly loads the driver
> controlling the brightness change. (?)

Is this really a thing of "driver"? Yes, I know: "Modern" laptops
use software to "connect" the keys to the brightness, whereas old
laptops did that "in hardware" somehow - independent from the OS,
even working in BIOS or during bluescreens.

I could imagine that somehow, when the OS and the GUI is loaded,
the keys designed to adjust brightness emit a "normal" key code
that the GUI (here: X's keyboard input machanism) picks up and
does something stupid with it. You can easily check for that
possibility: install the "xev" (X event viewer) port and press
those keys. Look for "KeyPress" entries. What happens?

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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