Broadcast RGB property and Intel video driver

[Tom Horsley]

For the longest time, I've had this suspicion that some
update to the Intel graphics driver has made it screw
up the range of colors that can be displayed.

I just found this command:

xrandr --output HDMI2 --set "Broadcast RGB" Full

And the result is magical, the thin mist that had been
obscuring my screen was blown away, and everything is
crystal clear again.

But, it makes the screen flicker badly, and the Samsung
TV I'm using is slightly out of sync till I power cycle
it (or switch modes and switch back).

Anyone know if there is some way to set this permanently
as the default mode for the display rather than having to
run xrandr to change it at runtime?

(Apparently the default "Automatic" setting for this
property guesses wrong).

[Ed Greshko]

On 06/24/13 05:56, Tom Horsley wrote:
> For the longest time, I've had this suspicion that some
> update to the Intel graphics driver has made it screw
> up the range of colors that can be displayed.
>
> I just found this command:
>
> xrandr --output HDMI2 --set "Broadcast RGB" Full
>
> And the result is magical, the thin mist that had been
> obscuring my screen was blown away, and everything is
> crystal clear again.
>
> But, it makes the screen flicker badly, and the Samsung
> TV I'm using is slightly out of sync till I power cycle
> it (or switch modes and switch back).
>
> Anyone know if there is some way to set this permanently
> as the default mode for the display rather than having to
> run xrandr to change it at runtime?
>
> (Apparently the default "Automatic" setting for this
> property guesses wrong).

Just the smallest amount of googling suggests that an xorg.conf option exists for this....

Option "BROADCAST_RGB"   "0"   or   "1"

[Tom Horsley]

On Mon, 24 Jun 2013 06:30:00 +0800
Ed Greshko wrote:
> Just the smallest amount of googling suggests that an xorg.conf option exists for this....
>
> Option "BROADCAST_RGB"   "0"   or   "1"

Absolutely true, and a fantastically large amount of
googling doesn't disclose which section it is supposed to
go in to be associated with the HDMI2 output or how
to construct the fragment of xorg.conf that I need
to stick in the /etc/X11/xorg.conf.d directory
to convey it to the driver :-).

[Reindl Harald]

Am 24.06.2013 00:47, schrieb Tom Horsley:
> On Mon, 24 Jun 2013 06:30:00 +0800
> Ed Greshko wrote:
> > Just the smallest amount of googling suggests that an xorg.conf option exists for this....
> >
> > Option "BROADCAST_RGB"   "0"   or   "1"
>
> Absolutely true, and a fantastically large amount of
> googling doesn't disclose which section it is supposed to
> go in to be associated with the HDMI2 output or how
> to construct the fragment of xorg.conf that I need
> to stick in the /etc/X11/xorg.conf.d directory
> to convey it to the driver :-)

google hit #5 here:
http://manpages.ubuntu.com/manpages/maverick/man4/intel.4.html

SYNOPSIS

Section "Device"
         Identifier "devname"
         Driver "intel"
         ...
       EndSection
.........................

[Ed Greshko]

On 06/24/13 06:47, Tom Horsley wrote:
> On Mon, 24 Jun 2013 06:30:00 +0800
> Ed Greshko wrote:
> > Just the smallest amount of googling suggests that an xorg.conf option exists for this....
> >
> > Option "BROADCAST_RGB"   "0"   or   "1"
>
> Absolutely true, and a fantastically large amount of
> googling doesn't disclose which section it is supposed to
> go in to be associated with the HDMI2 output or how
> to construct the fragment of xorg.conf that I need
> to stick in the /etc/X11/xorg.conf.d directory
> to convey it to the driver :-).

Yeah, well I'm not going to be much help with that at the moment since I don't have the time to really research and bring back my xorg.conf skills.   :-(

Most likely placed in the "Screen" or "Device" section.  Probably needs to be combined with the ConnectedMonitor option.

FWIW, not all video drivers support that option.  The binary NVidia drivers don't support it AFAIK.

Good luck.

[Tom Horsley]

On Mon, 24 Jun 2013 07:37:12 +0800
Ed Greshko wrote:
> Yeah, well I'm not going to be much help with that at the moment since I don't have the time to really research and bring back my xorg.conf skills.   :-(

Me either :-).

I finally settled on running a script that uses xrandr
to check the current setting and change it to Full
if it isn't already (which reduces the number of
monitor flickers I have to see :-).

I run it from  the /etc/X11/xinit/xinitrc.d/ directory.

Of course the best thing would be a kernel boot option
to set the default so I wouldn't have to see the mist
obscuring my boot messages either, but I don't think
the driver has such an option :-).

[poma]

On 24.06.2013 01:37, Ed Greshko wrote:
…
> Most likely placed in the "Screen" or "Device" section.  Probably needs to be combined with the ConnectedMonitor option.
>
> FWIW, not all video drivers support that option.  The binary NVidia drivers don't support it AFAIK.

Module specific properties aren't exposed to *conf. ;)

poma