Re: monitor setting in gnome using new randr 1.5 option

[Dave Airlie <airlied gmail com>]

On 18 November 2015 at 10:09, Stephen Adler <adler stephenadler com> wrote:
> On 11/11/2015 02:48 PM, drago01 wrote:
> > On Wed, Nov 11, 2015 at 8:22 PM, Stephen Adler <adler stephenadler com>
> > wrote:
> > > Thanks,
> > >
> > >
> > > On 11/11/2015 10:34 AM, Bastien Nocera wrote:
> > > > Hey,
> > > >
> > > > On Wed, 2015-11-11 at 09:50 -0500, Stephen Adler wrote:
> > > > > Guys,
> > > > >
> > > > > I have 3 MST type 4K monitor hooked up to my PC and I've been trying
> > > > > to
> > > > > get linux to work properly and have been chopping at the bit for
> > > > > randr
> > > > > 1.5 to come out which is supposed to solve the MST tile issue which
> > > > > 4K
> > > > > monitors suffer from.
> > > > >
> > > > > Is there something I have to do, configure some file in /etc/
> > > > > somewhere
> > > > > which would define which tiles make up a monitor? I'm not sure if
> > > > > there
> > > > > is something I have to do, or if gnome is supposed to take care of
> > > > > the
> > > > > tiling for me, by somehow defining which tiles are part of which
> > > > > monitor.
> > > > >
> > > > > to make matters worse, I have a pair of nvidia cards for which the
> > > > > nvidia driver does not support xorg 1.18, so I had to downgrade to
> > > > > xorg
> > > > > 1.17. In doing so, I still have randr 1.5 installed but I don't know
> > > > > if
> > > > > randr 1.5 needs xorg 1.18 or if the two are decoupled enough so that
> > > > > I
> > > > > can run xorg 1.17 with the nvidia driver and get the benefits of the
> > > > > monitor features of randr 1.5.
> > > > >
> > > > > Anyone know the answer to all this? I owe you big if you do.
> > > >
> > > > A question better asked on X.org mailing-lists, but if you need to use
> > > > the NVidia drivers, it'd be best to wait until they release new drivers
> > > > to avoid mix'n'matching. You can double-check the version of XRandR
> > > > supported by the server with "xrandr --version".
> > > >
> > > > With XRandR 1.5, and GNOME 3.18, MST monitors should just work. If they
> > > > don't, file a bug against mutter, which handles programming the video
> > > > outputs.
> > > >
> > > > Cheers
> > > When you say, it should "just work", do you mean that the tiling problem
> > > I'm
> > > having now will disapear since gnome desktop will figure out that I only
> > > have 3 monitors and not 6 tiles. Currently, when I go to configure the
> > > displays, it tells me I have 6 displays to work with (two per physical
> > > monitor). If all is right, then the gnome display configuration tool will
> > > only show me 3 monitors to configure? I hope this is what your telling
> > > me.
> > > :)
> >
> > Yes thats how it is supposed to work afaik (no hardware here to verify).
>
> I installed fedora 23 which has Xorg 1.18 to go with it. I also installed
> the latest version of the nvidia driver which now supports Xorg 1.18....
> So I'm now looking at xrandr and this is what it reports....
>
> [root office01 ~]# xrandr --version
> xrandr program version       1.4.3
> Server reports RandR version 1.5
>
>
> Is this the expected output? 1.4.3 and 1.5? Or is this some kind of fedora
> specific port of xrandr in which they didn't push through the 1.5 version?
>
> In anycase, the xrandr --prop output looks like this....
>
> I guess the observation I have is that I still got my MST split screen
> looking desktop when running my monitor in MST/DP1.2 mode. I had to turn off
> two of the monitors to get a stable setup with the nvidia driver for my
> GeForce GTX 970 card.
>
> So the question is, should I proceed to submit a bug report? Or is Fedora 23
> not really fully randr 1.5 compliant?

The nvidia driver isn't exposing tile properties.

Dave.