[Nouveau] support for dp 1.2

[Ilia Mirkin]

On Tue, Jun 16, 2015 at 3:33 PM, Stephen Adler <adler at stephenadler.com> wrote:
> Guys,
>
> Is there support for display port 1.2 with the nouveau driver and GTX
> 970?
>
> I have a dell 4K monitor and to run it in 4K mode at 60Hz I need to
> configure the monitor to run version 1.2 of the display port protocol.
> the nouveau driver works well with display port 1.1 but I only get a
> 30Hz refresh rate at 4K resolution.

The DP 1.2 540MHz rate should be supported. However there is presently
no MST support, so if the monitor has 2 internal panels, that won't
pan out so well (yet).

Also note that the GTX 970 requires signed firmware from NVIDIA to use
any acceleration, and we haven't quite yet figured out how to get that
going. This means that all you get is modesetting, no acceleration.
Esp with a 4K screen, using llvmpipe may feel slow if you use a GL
compositor, as many modern desktops do.

  -ilia