Re: sysctl and screen brightness

[Todd Gruhn <tgruhn2%gmail.com@localhost>]

HMMMMM. Did I uncover something?

On Fri, Sep 10, 2021 at 11:14 AM Rocky Hotas <rockyhotas%firemail.cc@localhost> wrote:
>
> On set 10 10:39, Benny Siegert wrote:
> > It depends on what the exact machine is. Try looking through the
> > output of "sysctl hw" or "sysctl machdep" for options with
> > "brightness", "backlight", or similar in their names.
>
> I have (in a laptop)
>
> 000:02:0: Intel Sandy Bridge (mobile) GT2 Integrated Graphics Device (VGA display, revision 0x09)
> 001:00:0: ATI Technologies Radeon HD 6400M (VGA display)
>
> I think the first one is not used. According to your suggestion, the
> only relevant items in the whole `sysctl -a' seem to be:
>
> hw.acpi.acpiout1.brightness = 100
> hw.acpi.acpiout2.brightness = 100
> hw.acpi.acpiout6.brightness = 100
> hw.drm2.i915.invert_brightness = 0
> hw.drm2.radeon_backlight = -1
>
> If I try (as root) to change the values of any of them, the operation is
> permitted, but it has no effect (hw.acpi.acpiout* still remains at their
> value 100), or it is not permitted:
>
> sysctl: hw.drm2.i915.invert_brightness: Operation not permitted
>
> sysctl: hw.drm2.radeon_backlight: Operation not permitted
>
> In fact, I am not able to modify the brightness of my screen: if I press
> the F2-F3 keys which should do this, nothing changes.
>
> This is just FYI, as another example of hardware. Maybe the NetBSD driver
> still doesn't offer a full flexibility with some configurations like
> this one.
>
> Bye!
>
> Rocky