[prev in list] [next in list] [prev in thread] [next in thread]
List: freedesktop-xorg
Subject: Re: Xorg framebuffer and brightness of screen
From: Riza Dindir <riza.dindir () gmail ! com>
Date: 2021-11-16 3:26:58
Message-ID: CA+ek4BGgei9K+ONxbf9YsEuFiKvSBOD-17eVwyVSwC7h4avs3g () mail ! gmail ! com
[Download RAW message or body]
Thank you for very much for the information. Was thinking that playing with
the gamma might be a solution.
Regards.
Riza
On Mon, Nov 15, 2021, 19:33 Alex Deucher <alexdeucher@gmail.com> wrote:
> On Fri, Nov 12, 2021 at 11:21 PM Riza Dindir <riza.dindir@gmail.com>
> wrote:
> >
> > Hello Alex,
> >
> > Isn't there a software based solution to set the brightness in xorg?
>
> Not really. You need some interface to talk to the backlight
> controller, either via software via a driver or via some firmware
> interface like ACPI if the platform supports it. You can also adjust
> the gamma on the display which will give the perception of changes in
> brightness, but it won't actually change the levels of the backlight
> itself. That said, you need driver support to adjust the gamma as
> well.
>
> Alex
>
> >
> > Riza
> >
> > On Fri, Nov 12, 2021 at 11:37 PM Alex Deucher <alexdeucher@gmail.com>
> wrote:
> > >
> > > On Fri, Nov 12, 2021 at 12:36 AM Riza Dindir <riza.dindir@gmail.com>
> wrote:
> > > >
> > > > Hello Ken.
> > > >
> > > > On Fri, Nov 12, 2021 at 12:56 AM Ken Moffat <zarniwhoop@ntlworld.co=
m>
> 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 republica=
n
> > > > > 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 m=
e
> 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-ou=
tput-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
> > >
> > >
> > > >
> > > > >
> > > > > =C4=B8en
> > > > > --
> > > > > 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.=E2=
=80=9D
> > > >
> > > > Regards,
> > > > Riza
>
[Attachment #3 (text/html)]
<div dir="auto"><div>Thank you for very much for the information. Was thinking that \
playing with the gamma might be a solution.</div><div dir="auto"><br></div><div \
dir="auto">Regards.</div><div dir="auto">Riza</div><div dir="auto"><br><div \
class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Mon, Nov 15, \
2021, 19:33 Alex Deucher <<a \
href="mailto:alexdeucher@gmail.com">alexdeucher@gmail.com</a>> \
wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 \
.8ex;border-left:1px #ccc solid;padding-left:1ex">On Fri, Nov 12, 2021 at 11:21 PM \
Riza Dindir <<a href="mailto:riza.dindir@gmail.com" target="_blank" \
rel="noreferrer">riza.dindir@gmail.com</a>> wrote:<br> ><br>
> Hello Alex,<br>
><br>
> Isn't there a software based solution to set the brightness in xorg?<br>
<br>
Not really. You need some interface to talk to the backlight<br>
controller, either via software via a driver or via some firmware<br>
interface like ACPI if the platform supports it. You can also adjust<br>
the gamma on the display which will give the perception of changes in<br>
brightness, but it won't actually change the levels of the backlight<br>
itself. That said, you need driver support to adjust the gamma as<br>
well.<br>
<br>
Alex<br>
<br>
><br>
> Riza<br>
><br>
> On Fri, Nov 12, 2021 at 11:37 PM Alex Deucher <<a \
href="mailto:alexdeucher@gmail.com" target="_blank" \
rel="noreferrer">alexdeucher@gmail.com</a>> wrote:<br> > ><br>
> > On Fri, Nov 12, 2021 at 12:36 AM Riza Dindir <<a \
href="mailto:riza.dindir@gmail.com" target="_blank" \
rel="noreferrer">riza.dindir@gmail.com</a>> wrote:<br> > > ><br>
> > > Hello Ken.<br>
> > ><br>
> > > On Fri, Nov 12, 2021 at 12:56 AM Ken Moffat <<a \
href="mailto:zarniwhoop@ntlworld.com" target="_blank" \
rel="noreferrer">zarniwhoop@ntlworld.com</a>> wrote:<br> > > > ><br>
> > > > On Thu, Nov 11, 2021 at 10:16:18AM +0300, Riza Dindir wrote:<br>
> > > > > Hello Ken<br>
> > > > ><br>
> > > > > I am using gop, and a framebuffer. When i try to use the \
xrandr, it says<br> > > > > > "gamma is set to 0", or \
"failed to get size of gamma for output default".<br> > > > > \
><br> > > > > > I can set the gamma uaing xgamma and in the \
xorg.conf file.<br> > > > > ><br>
> > > > > Riza<br>
> > > > ><br>
> > > > No idea what gop is - google suggests it's the american \
republican<br> > > > > party ;-)<br>
> > ><br>
> > > :D That is the graphics output protocol.<br>
> > ><br>
> > > My radeon device is not recognized by the kernel (netbsd) and I am<br>
> > > using a framebuffer.<br>
> > ><br>
> > > ><br>
> > > > Did you search for that "failed to get" message ? \
Google gives me a lot of<br> > > > > different matches, some for failing \
to correctly add a new mode,<br> > > > > others for running with nvidia \
drivers or in virtualbox, or with out<br> > > > > of date \
manufacturer's video driver.<br> > > > > <a \
href="https://askubuntu.com/questions/441040/failed-to-get-size-of-gamma-for-output-default-when-trying-to-add-new-screen-res" \
rel="noreferrer noreferrer" \
target="_blank">https://askubuntu.com/questions/441040/failed-to-get-size-of-gamma-for-output-default-when-trying-to-add-new-screen-res</a><br>
> > > ><br>
> > > > For an ubuntu-based kernel with at-the-time recent intel \
graphics<br> > > > > hardware, adding a boot arg to enable alpha-quality \
intel support.<br> > > > > <a \
href="https://itectec.com/ubuntu/ubuntu-xrandr-failed-to-get-size-of-gamma-for-output-default-for-mdp-type-connection/" \
rel="noreferrer noreferrer" \
target="_blank">https://itectec.com/ubuntu/ubuntu-xrandr-failed-to-get-size-of-gamma-for-output-default-for-mdp-type-connection/</a><br>
> > > ><br>
> > > > In short, finding the answer really does seem to depend on \
what<br> > > > > hardware and distro are in use. I'm assuming \
you're using some sort<br> > > > > of linux.<br>
> > ><br>
> > > What I am trying to do is reduce the brightness of the LCD on my<br>
> > > laptop. Since I am using a framebuffer, I thought that I could do \
that<br> > > > with the gamma values. But xrandr fails with a message \
relating to<br> > > > the gamma values being 0 or not set.<br>
> ><br>
> > You might get lucky if your system supports backlight control via<br>
> > hotkeys or some ACPI interface which your BSD supports. If not, then<br>
> > not. There's no backlight control in GOP.<br>
> ><br>
> > Alex<br>
> ><br>
> ><br>
> > ><br>
> > > ><br>
> > > > ĸen<br>
> > > > --<br>
> > > > Vetinari smiled. "Can you keep a secret, Mister \
Lipwig?"<br> > > > > "Oh, yes, sir. I've kept \
lots."<br> > > > > "Capital. And the point is, so can I. You do \
not need to know."<br> > > ><br>
> > > Regards,<br>
> > > Riza<br>
</blockquote></div></div></div>
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic