Xorg framebuffer and brightness of screen

[Riza Dindir]

Hello Alex,

Isn't there a software based solution to set the brightness in xorg?

Riza

On Fri, Nov 12, 2021 at 11:37 PM Alex Deucher <alexdeucher at gmail.com> wrote:
>
> On Fri, Nov 12, 2021 at 12:36 AM Riza Dindir <riza.dindir at gmail.com> wrote:
> >
> > Hello Ken.
> >
> > On Fri, Nov 12, 2021 at 12:56 AM Ken Moffat <zarniwhoop at ntlworld.com> wrote:
> > >
> > > On Thu, Nov 11, 2021 at 10:16:18AM +0300, Riza Dindir wrote:
> > > > Hello Ken
> > > >
> > > > I am using gop, and a framebuffer. When i try to use the xrandr, it says
> > > > "gamma is set to 0", or "failed to get size of gamma for output default".
> > > >
> > > > I can set the gamma uaing xgamma and in the xorg.conf file.
> > > >
> > > > Riza
> > > >
> > > No idea what gop is - google suggests it's the american republican
> > > party ;-)
> >
> > :D That is the graphics output protocol.
> >
> > My radeon device is not recognized by the kernel (netbsd) and I am
> > using a framebuffer.
> >
> > >
> > > Did you search for that "failed to get" message ?  Google gives me a lot of
> > > different matches, some for failing to correctly add a new mode,
> > > others for running with nvidia drivers or in virtualbox, or with out
> > > of date manufacturer's video driver.
> > > https://askubuntu.com/questions/441040/failed-to-get-size-of-gamma-for-output-default-when-trying-to-add-new-screen-res
> > >
> > > For an ubuntu-based kernel with at-the-time recent intel graphics
> > > hardware, adding a boot arg to enable alpha-quality intel support.
> > > https://itectec.com/ubuntu/ubuntu-xrandr-failed-to-get-size-of-gamma-for-output-default-for-mdp-type-connection/
> > >
> > > In short, finding the answer really does seem to depend on what
> > > hardware and distro are in use.  I'm assuming you're using some sort
> > > of linux.
> >
> > What I am trying to do is reduce the brightness of the LCD on my
> > laptop. Since I am using a framebuffer, I thought that I could do that
> > with the gamma values. But xrandr fails with  a message relating to
> > the gamma values being 0 or not set.
>
> You might get lucky if your system supports backlight control via
> hotkeys or some ACPI interface which your BSD supports.  If not, then
> not.  There's no backlight control in GOP.
>
> Alex
>
>
> >
> > >
> > > ĸen
> > > --
> > > Vetinari smiled. "Can you keep a secret, Mister Lipwig?"
> > > "Oh, yes, sir. I've kept lots."
> > > "Capital. And the point is, so can I. You do not need to know.”
> >
> > Regards,
> > Riza