Re: output setup and configuration, what lives where?

[Bastien Nocera <hadess hadess net>]

On Mon, 2014-10-13 at 16:53 +1000, Dave Airlie wrote:
> Hey,
>
> So I've been looking at 4K monitors that require DP MST and present as
> two screens with some tiling info in the EDID extensions, and I've
> been taking a look at how to integrate these with gnome.
>
> Just to clear things up, I tried to hide these in the kernel, the side
> effects were too messy to cover up, and stuff broke in wierd ways, so
> I've decided to follow Windows and push this up a few levels.
>
> So I've built a kernel property to describe tiles, and passed it
> through X to test, and hacked on mutter 3.10, so
>
> a) windows maximize properly
> b) initial mutter configuration picks a sane config.
>
> (cgit.freedesktop.org/~airlied/mutter - will eventually have it).
>
> Now the question is what else needs changing for this, I know I should
> probably start to target master or least F21 versions and I'll
> probably get to that,
>
> I'm getting the feeling at least,
> gnome-desktop
> and
> gnome-control-center
>
> will need work, control-center will probably need design work so the
> UI doesn't suck for this use-case.

"Make my monitor work" isn't a new use case :)

> I'm just not sure how things like monitors.xml fit in, who writes this
> file, who reads it, is there
> some stuff talking over dbus here, does gnome-session-daemon get
> involved anywhere etc, so pointers/answers etc all appreciated.

The only place you should need to modify would be mutter, which contains
the X and Wayland backends for monitor configuration. If you expose your
monitor tiles as a single monitor there, it will show up as a single
monitor for anything that cares about monitors in the GNOME stack
(except gtk+ which uses XRandR directly for monitor sizes).

Cheers