Mackbook pro nvidia based video backlight

Julian Elischer julian at
Fri Jan 30 01:53:49 PST 2009

Ed Schouten wrote:
> * Alexander Leidinger <Alexander at> wrote:
>>> The ideal solution would be to integrate it into vidcontrol, calling
>>> some kind of ioctl on the TTY/consolectl, but syscons is too brainless
>>> to know anything about hardware specific features.
>> Here we are back to what was proposed instead of sysctl. I have to admin 
>> that I'm confused now about what you propose as a good solution.
> Well, I wouldn't like it if we create character devices, just to let it
> implement a single ioctl() ("/dev/backlight", for example). There is
> only 1 parameter that's adjustable, namely the backlight intensity. A
> sysctl is a good place to store such things.

I don't know.... you could flash morse code in response to a write.

> In my opinion we should only use character devices for devices that
> have the semantics of a file descriptor, namely to read/write data to
> it, perform select(), etc. Saying sysctl is bad, because it doesn't
> allow any permissions should be considered to be a defect of sysctl, not
> an advantage of devfs.
> The reason why I prefer consolectl, is because it already exists and
> allows related graphics parameters to be configured.

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